Repository: nfdi4cat/voc4cat-tool (language: python)

Issue:
Prepare release 0.4.0 (targeting M4)
Update readme

- [x] Get rid of references to hidden resources.
- [x] Describe changes to voc4cat options

Update and check examples

- [x] all Excel files in examples-folder
- [x] code examples in readme


Discussion / hints:

Fix patch:
diff --git a/.gitignore b/.gitignore
index 92923d8..028a0c7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,21 +1,9 @@
-# Created by https://www.toptal.com/developers/gitignore/api/jupyternotebooks,python
-
-### JupyterNotebooks ###
-# gitignore template for Jupyter Notebooks
-# website: http://jupyter.org/
+# Jupyter Notebooks
 
 .ipynb_checkpoints
 */.ipynb_checkpoints/*
 
-# IPython
-profile_default/
-ipython_config.py
-
-# Remove previous ipynb_checkpoints
-#   git rm -r .ipynb_checkpoints/
-
-### Python ###s
-# Byte-compiled / optimized / DLL files
+# Python - Byte-compiled / optimized / DLL files
 __pycache__/
 *.py[cod]
 *$py.class
@@ -72,59 +60,12 @@ cover/
 *.mo
 *.pot
 
-# Django stuff:
-*.log
-local_settings.py
-db.sqlite3
-db.sqlite3-journal
-
-# Flask stuff:
-instance/
-.webassets-cache
-
-# Scrapy stuff:
-.scrapy
-
 # Sphinx documentation
 docs/_build/
 
-# PyBuilder
-.pybuilder/
-target/
-
-# Jupyter Notebook
-
-# IPython
-
-# pyenv
-#   For a library or package, you might want to ignore these files since the code is
-#   intended to run in multiple environments; otherwise, check them in:
-# .python-version
-
-# pipenv
-#   According to pypa/pipenv#598, it is recommended to include Pipfile.lock in version control.
-#   However, in case of collaboration, if having platform-specific dependencies or dependencies
-#   having no cross-platform support, pipenv may install dependencies that don't work, or not
-#   install all needed dependencies.
-#Pipfile.lock
-
-# poetry
-#   Similar to Pipfile.lock, it is generally recommended to include poetry.lock in version control.
-#   This is especially recommended for binary packages to ensure reproducibility, and is more
-#   commonly ignored for libraries.
-#   https://python-poetry.org/docs/basic-usage/#commit-your-poetrylock-file-to-version-control
-#poetry.lock
-
 # PEP 582; used by e.g. github.com/David-OConnor/pyflow
 __pypackages__/
 
-# Celery stuff
-celerybeat-schedule
-celerybeat.pid
-
-# SageMath parsed files
-*.sage.py
-
 # Environments
 .venv
 env/
@@ -143,9 +84,6 @@ venv.bak/
 # Rope project settings
 .ropeproject
 
-# mkdocs documentation
-/site
-
 # mypy
 .mypy_cache/
 .dmypy.json
@@ -160,15 +98,5 @@ dmypy.json
 # Cython debug symbols
 cython_debug/
 
-# PyCharm
-#  JetBrains specific template is maintained in a separate JetBrains.gitignore that can
-#  be found at https://github.com/github/gitignore/blob/main/Global/JetBrains.gitignore
-#  and can be added to the global gitignore or merged into this file.  For a more nuclear
-#  option (not recommended) you can uncomment the following to ignore the entire idea folder.
-#.idea/
-
 # setuptools_scm generated version file
 _version.py
-
-# output dir
-outbox/
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
deleted file mode 100644
index f8b1f8b..0000000
--- a/.gitlab-ci.yml
+++ /dev/null
@@ -1,48 +0,0 @@
-# Official language image. Look for the different tagged releases at:
-# https://hub.docker.com/r/library/python/tags/
-image: python:3.10-bullseye
-
-# Change pip's cache directory to be inside the project directory since we can
-# only cache local items.
-variables:
-  PIP_CACHE_DIR: "$CI_PROJECT_DIR/.cache/pip"
-
-# Pip's cache doesn't store the python packages
-# https://pip.pypa.io/en/stable/topics/caching/
-#
-# If you want to also cache the installed packages, you have to install
-# them in a virtualenv and cache it as well.
-cache:
-  paths:
-    - .cache/pip
-    - .venv/
-
-before_script:
-  - python --version
-  - python -m venv .venv
-  - source .venv/bin/activate
-  - python -m pip install -U pip
-
-tests:
-  stage: test
-  script:
-    # install project inlcuding optional test dependencies
-    - pip install -U .[tests]
-    - pytest
-
-# https://docs.gitlab.com/ee/ci/testing/test_coverage_visualization.html#python-example
-# https://pytest-cov.readthedocs.io/en/latest/readme.html#usage
-coverage:
-  stage: test
-  needs: [tests]
-  script:
-    # Install package including tests-extras as editable to determine coverage
-    - pip install -e .[tests]
-    - python -m coverage run -m pytest
-    - coverage xml
-  coverage: '/(?i)total.*? (100(?:\.0+)?\%|[1-9]?\d(?:\.\d+)?\%)$/'
-  artifacts:
-    reports:
-      coverage_report:
-        coverage_format: cobertura
-        path: coverage.xml
diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..99ea2c5
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,30 @@
+# Change log
+
+## Release x.y.z (2023-MM-DD)
+
+Features:
+
+- ...
+
+Bug fixes:
+
+- ...
+
+Changes:
+
+- ...
+
+
+## Release 0.4.0 (2023-03-dd)
+
+First public release of voc4cat on github.
+
+
+## Releases before 0.4.0
+
+Before 0.4.0 the code was in alpha state and kept private.
+There was no need for a high-level documentaion of changes.
+See git commit log and the issues & milestones in this repository for the early history.
+
+Just before 0.4.0 the code was migrated from a private gitlab instance to github.
+The transfer went OK but not perfect (gitlab-MRs were not well converted to github-PRs).
diff --git a/README.md b/README.md
index 1656f5a..409e96a 100644
--- a/README.md
+++ b/README.md
@@ -1,56 +1,31 @@
-This is the repository
+# SKOS vocabulary creation & maintenance with GitHub & Excel
 
-- for working in NFDI4Cat on **Vocabularies for analytics, synthesis and heterogeneous catalysis**.
-- for **voc4cat** a script that adds additional options to the original vocexcel tool (without changing or copying any original vocexcel code)
-- for developing a **gitlab-based, CI-supported workflow for maintaining vocabularies.**
+## Overview
 
-Additional files and notes from the subgroup can be found in the HLRS cloud:
+**[voc4cat](https://github.com/nfdi4cat/voc4cat-playground)** is a vocabulary for catalysis developed in NFDI4Cat.
 
-- [Folder of TA1 subgroup Analytics-Synthesis-HeterogeneousCatalysis](https://edocs.hlrs.de/nextcloud/apps/files/?dir=/NFDI4Cat/Project-related%20activities/Task%20Areas/TA1/Subgroup_Analytics-Synthesis-HeterogCatalysis&fileid=155479)
-- [Top level folder for TA1](https://edocs.hlrs.de/nextcloud/apps/files/?dir=/NFDI4Cat/Project-related%20activities/Task%20Areas/TA1&fileid=96729)
+Related to voc4cat we developed a **toolbox for collaboratively maintaining SKOS vocabularies on github using Excel** (xlsx) as user-friendly interface. It consists of several parts:
 
-# Gitlab-based vocabulary development and maintenance
+- **voc4cat-tool** (this repository)
+  - A commandline tool that adds additional options to [vocexcel](https://github.com/nfdi4cat/VocExcel) without changing or copying any code from the original vocexcel project (GPL 3 licensed).
+- **[voc4cat-template](https://github.com/nfdi4cat/voc4cat-template)**
+  - A github project template for managing SKOS-vocabularies using a GitHub-based workflows including automation by gh-actions.
+- **[voc4cat-playground](https://github.com/nfdi4cat/voc4cat-playground)**
+  - A testbed for playing with the voc4cat workflow. The playground is a test-deployment of the voc4cat-template.
 
-All vocabularies that have gone through the standard gitlab process of
 
-- submission of merge request,
-- review of merge request,
-- approval of merge request
-
-finally land in the folder `vocabularies`.
-
-## New vocabularies
-
-Please use the Excel file from the template folder to create vocabularies that are compatible with this repository.
-If you already have a turtle file, you may convert it with voc4cat to xlsx (Excel).
-Be careful that you use a different name for your vocabulary then the ones already present in the `vocabularies` folder.
-
-The rest of the process is the same as in "Update existing vocabularies" below.
-
-## Update existing vocabularies
-
-To add or change details in an existing vocabulary, submit a pull request with an updated Excel-file that has the same name as the vocabulary that you want to update
-(see `vocabularies` folder for the names of existing vocabularies).
-If you don't have an Excel file but just the turtle file, you can use voc4cat (see below) to convert the turtle file to xlsx (Excel).
-
-Upon submission of the merge request, the Excel file is automatically processed by a CI pipeline.
-The results (updated Excel-file, documentation, dendogram, processing log) will be available after about 1 min as download on the merge request page (as so called "artifact").
-If you need to fix something just update the merge request branch. This will trigger the pipeline to run again.
-
-Please describe your changes and the motivation for the changes in the merge request note(s) or link to an issue with this information. This will help reviewers to decide on the proposed change.
-
-Finally, when the proposed merge request is accepted, your changes will be integrated in the vocabularies in the folder `vocabularies`.
-
-# Tool voc4cat
+## Commandline tool voc4cat
 
 To support what is not provided by the original vocexcel project we have developed this wrapper "voc4cat" that augments vocexcel with additional options like
 
 - Checking our NFDI4Cat-Excel template
-- Enriching our NFDI4Cat-Excel template (e.g. automatically add IRIs)
+- Enriching our NFDI4Cat-Excel template (e.g. add IRIs)
 - Processing all files in a folder at once
 - Generating documentation (with [ontospy](http://lambdamusic.github.io/Ontospy/))
 - Support for expressing concept-hierarchies by indentation.
 
+Since mid 2022 voc4cat should be used with our vocexcel fork [nfdi4cat/vocexcel](https://github.com/nfdi4cat/vocexcel). The original project (now at [RDFlib/vocexcel](https://github.com/RDFLib/VocExcel)) changed its templates substantially which made it too cumbersome to keep our code and the customized templates compatible.
+
 ## Installation
 
 The installation requires internet access since we install vocexcel directly from GitHub.
@@ -61,20 +36,21 @@ Preconditions:
 - Python (3.8 or newer)
 
 voc4cat works on windows, linux and mac. However, the command examples below assume that you work on windows
-and that the [launcher](https://docs.python.org/3.10/using/windows.html#python-launcher-for-windows) is also installed.
-The launcher is included by default in Windows installers from [python.org](https://www.python.org/downloads/)
+and that the [launcher](https://docs.python.org/3.11/using/windows.html#python-launcher-for-windows) is also installed.
+The launcher is included by default in Windows installers from [python.org](https://www.python.org/downloads/). 
+If you don't have the launcher replace `py` by `python` (or `python3`, depending on your OS) in the commands below.
 
 ## Installation steps
 
 Checkout this repository
 
-`git clone https://gitlab.fokus.fraunhofer.de/nfdi4cat/ta1-ontologies/voc4cat-tool.git`
+`git clone https://github.com/nfdi4cat/voc4cat-tool.git`
 
 Enter the directory to which you cloned.
 
 `cd voc4cat-tool`
 
-Create a virtual environment in a local subfolder ".venv" (Note that the command is for windows. Replace "py" with "python3" on other platforms.):
+Create a virtual environment in a local subfolder ".venv" (This command is for windows. Replace "py" with "python3" on other platforms.):
 
 `py -m venv .venv`
 
@@ -82,41 +58,46 @@ Activate the virtual environment (This is again for windows).
 
 `.venv\scripts\activate.bat` (cmd) or `.venv\scripts\Activate.ps1` (powershell)
 
-Update the packages in the virtual environment.
+Update pip in the virtual environment.
 
-`py -m pip install -U pip setuptools`
+`py -m pip install -U pip`
 
 Install voc4cat into the virtual environment.
 
 `pip install .`
 
+To install including all development tools use `pip install .[dev]` for just the test tools us `pip install .[tests]`. For tests we use [pytest](https://docs.pytest.org).
+
+
 ## Typical use
 
-Run the wrapper and show the help message.
+Show a help message for the voc4cat command line tool with all available options.
 
-`voc4cat --help`
+`voc4cat --help` (or simply `voc4cat`)
 
-To create a new vocabulary use the NFDI4Cat-adjusted template from the  `templates` subfolder.
-Typically, when a new vocabulary is created you want to create IRIs from the preferred labels:
+To create a new vocabulary use the voc4Cat-adjusted template from the `templates` subfolder.
+You may first use simple temporary IRIs like (`new:my_term`). These temporary IRIS may be text based. 
 
-`voc4cat -i Your_Vocabulary.xlsx`
+With voc4cat you can later replace all IDs belonging to a given prefix (here `ex`) by numeric IDs e.g. starting from 1001:
 
-This will fill the IRI-column for all rows with missing IRI entries.
+`voc4cat --make-ids ex 1001 --output-directory output example/concept_hierarchy_043_4Cat.xlsx`
 
-Manually filling the Children URI (in sheet "Concepts") and Members URI (in sheet "Collections") with URIs can be tedious.
-An easier way to express hierarchies between concepts, is to use indentation. voc4Cat supports Excel-indentation (default).
-voc4cat can also convert other indentaions (e.g.by 3 spaces per level) into Excel-indentation.
+This will update all IRIs matching the `ex:`-prefix in the sheets "Concepts", "Additional Concept Features" and "Collections".
+
+Manually filling the Children URI (in sheet "Concepts") and Members URI (in sheet "Collections") with lists of IRIs can be tedious.
+An easier way to express hierarchies between concepts is to use indentation.
+voc4Cat understands Excel-indentation (the default) for this purpose but can also work with other indentation formats (e.g. by 3 spaces per level).
 voc4cat supports converting between indentation-based hierarchy and Children-URI hierarchy (both directions). For example, use
 
-`voc4cat --hierarchy-from-indent --output_directory output example/indent_043_4Cat.xlsx`
+`voc4cat --hierarchy-from-indent --output-directory output example/indent_043_4Cat.xlsx`
 
 or if you were using 3 spaces per level
 
-`voc4cat --hierarchy-from-indent --indent-separator "   " --output_directory output example/indent_3spaces_043_4Cat.xlsx`
+`voc4cat --hierarchy-from-indent --indent-separator "   " --output-directory output example/indent_3spaces_043_4Cat.xlsx`
 
-to convert to ChildrenURI-hierarchy. For ChildrenURI-hierarchy to Excel-indenation, use
+to convert to ChildrenURI-hierarchy. For ChildrenURI-hierarchy to Excel-indentation, use
 
-`voc4cat --hierarchy-to-indent --output_directory output example/concept_hierarchy_043_4Cat.xlsx`
+`voc4cat --hierarchy-to-indent --output-directory output example/concept_hierarchy_043_4Cat.xlsx`
 
 Finally, the vocabulary file can be converted to turtle format. In this case the wrapper script passes the job on to vocexcel:
 
@@ -124,18 +105,23 @@ Finally, the vocabulary file can be converted to turtle format. In this case the
 
 A turtle file `vocabulary.ttl` is created in the same directory where the xlsx-file is located.
 
-It is also possible to create an xlsx file from a turtle file. Optionally a custom template (like we use here) can be specified:
+It is also possible to create an xlsx file from a turtle file. Optionally a custom template can be specified:
 
 `voc4cat --template template/VocExcel-template_043_4Cat.xlsx vocabulary.ttl`
 
 Options that are specific for vocexcel can be put at the end of a `voc4cat` command.
 Here is an example that forwards the `-e 3` and `-m 3` options to vocexcel and moreover demonstrates a complex combination of options (as used in CI):
 
-`voc4cat --add_IRI --check --forward --docs --output_directory outbox inbox-excel-vocabs/ -e 3 -m 3`
+`voc4cat --check --forward --docs --output-directory outbox inbox-excel-vocabs/ -e 3 -m 3`
 
-# Feedback and code contributions
+## Feedback and code contributions
 
 Just create an issue here. We appreciate any kind of feedback and reasoned criticism.
 
-If you want to contribute code, that is even better! We advise to create an issue to get feedback on your plans before you spent too much time on the problem.
+If you want to contribute code, we suggest to create an issue first to get early feedback on your plans before you spent too much time.
+
 By contributing you agree that your contributions fall under the project´s MIT license.
+
+## Acknowledgement
+
+This work was funded by the German Research Foundation (DFG) through the project "[NFDI4Cat](https://www.nfdi4cat.org) - NFDI for Catalysis-Related Sciences" (DFG project no. [441926934](https://gepris.dfg.de/gepris/projekt/441926934)), within the National Research Data Infrastructure ([NFDI](https://www.nfdi.de)) programme of the Joint Science Conference (GWK).
diff --git a/example/Photocatalysis_LIKAT_template043_final.ttl b/example/Photocatalysis_LIKAT_template043_final.ttl
index 4dd396c..3533f65 100644
--- a/example/Photocatalysis_LIKAT_template043_final.ttl
+++ b/example/Photocatalysis_LIKAT_template043_final.ttl
@@ -1,1614 +1,1643 @@
-@prefix cs: <http://example.org/nfdi4cat/photo> .
+@prefix cs: <https://example.org/nfdi4cat/photo_> .
 @prefix dcat: <http://www.w3.org/ns/dcat#> .
 @prefix dcterms: <http://purl.org/dc/terms/> .
 @prefix owl: <http://www.w3.org/2002/07/owl#> .
 @prefix skos: <http://www.w3.org/2004/02/skos/core#> .
 @prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
 
-<http://example.org/nfdi4cat/photo/area-of-deposited-film> a skos:Concept ;
-    dcterms:identifier "area-of-deposited-film"^^xsd:token ;
+cs:0001002 a skos:Concept ;
+    dcterms:identifier "photo_0001002"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/dimensions-of-deposited-film> ;
+    skos:broader cs:0001030 ;
     skos:definition "The area of the substrate covered by the deposited photocatalyst."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Area of deposited film"@en .
 
-<http://example.org/nfdi4cat/photo/batch-mode> a skos:Concept ;
-    dcterms:identifier "batch-mode"^^xsd:token ;
+cs:0001005 a skos:Concept ;
+    dcterms:identifier "photo_0001005"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/operation-mode> ;
+    skos:broader cs:0001089 ;
     skos:definition "Operation mode in which the reaction chamber is filled with the (reactant) gas(es) up to a certain pressure, and the photoreaction products acummulate over time."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Batch mode"@en .
 
-<http://example.org/nfdi4cat/photo/blank-measurements> a skos:Concept ;
-    dcterms:identifier "blank-measurements"^^xsd:token ;
+cs:0001006 a skos:Concept ;
+    dcterms:identifier "photo_0001006"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/photocatalytic-co2-reduction-experiment> ;
+    skos:broader cs:0001096 ;
     skos:definition "Measurements performed under a humidified inert gas atmosphre without the presence of CO2 but otherwise under the same conditions as a CO2 photoreduction experiment. These measurements provide an indirect proof of the origin of the carbon-containing products, as no products should be observed in the absence of CO2."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Blank measurements"@en .
 
-<http://example.org/nfdi4cat/photo/borosilicate-glass> a skos:Concept ;
-    dcterms:identifier "borosilicate-glass"^^xsd:token ;
+cs:0001007 a skos:Concept ;
+    dcterms:identifier "photo_0001007"^^xsd:token ;
     dcterms:provenance "https://www.suyogglassindustries.com/"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/glass-substrate> ;
+    skos:broader cs:0001063 ;
     skos:definition "A type of glass with silica and boron trioxide as the main glass-forming constituents. "@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Borosilicate glass"@en .
 
-<http://example.org/nfdi4cat/photo/brunauer-emmett-teller-surface-area-analysis> a skos:Concept ;
-    dcterms:identifier "brunauer-emmett-teller-surface-area-analysis"^^xsd:token ;
+cs:0001008 a skos:Concept ;
+    dcterms:identifier "photo_0001008"^^xsd:token ;
     dcterms:provenance "Self"@en ;
     skos:altLabel "BET"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/characterization-of-photocatalysts> ;
+    skos:broader cs:0001013 ;
     skos:definition "The study of physical adsorption of gas molecules on a solid surface for the calculation of the specific surface area of materials."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Brunauer-Emmett-Teller surface area analysis"@en .
 
-<http://example.org/nfdi4cat/photo/calibration-of-gas-chromatograph> a skos:Concept ;
-    dcterms:identifier "calibration-of-gas-chromatograph"^^xsd:token ;
+cs:0001010 a skos:Concept ;
+    dcterms:identifier "photo_0001010"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/gas-chromatography> ;
+    skos:broader cs:0001059 ;
     skos:definition "A process in which gaseous substances of known purity and concentration are introduced to the gas chromatograph and the respective area and retention time of the resulting peaks are identified. This process when concluded, allows for the calculation of concentrations of products and intermediates of the photoreaction."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Calibration of gas chromatograph"@en .
 
-<http://example.org/nfdi4cat/photo/calibration-of-mass-spectrometer> a skos:Concept ;
-    dcterms:identifier "calibration-of-mass-spectrometer"^^xsd:token ;
+cs:0001011 a skos:Concept ;
+    dcterms:identifier "photo_0001011"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/mass-spectrometry> ;
+    skos:broader cs:0001080 ;
     skos:definition "A process in which gaseous substances of known purity and concentration are introduced to the mass spectrometer and the respective mass-to-charge ratios are identified. This process when concluded, allows for the calculation of concentrations of products and intermediates of the photoreaction."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Calibration of mass spectrometer"@en .
 
-<http://example.org/nfdi4cat/photo/ceramic-substrate> a skos:Concept ;
-    dcterms:identifier "ceramic-substrate"^^xsd:token ;
+cs:0001012 a skos:Concept ;
+    dcterms:identifier "photo_0001012"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/material-of-substrate> ;
+    skos:broader cs:0001084 ;
     skos:definition "A  surface made of a ceramic material (e.g., alumina) serving as a substrate for the deposition of a photocatalyst."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Ceramic substrate"@en .
 
-<http://example.org/nfdi4cat/photo/characterization-of-photocatalysts-coll> a skos:Collection ;
-    dcterms:identifier "characterization-of-photocatalysts-coll"^^xsd:token ;
-    dcterms:isPartOf cs: ;
-    dcterms:provenance "Self"@en ;
-    skos:definition "A collection of techniques used to identify the (physico)chemical, morphological, structural, mechanical, optical and electrical properties of the syntesized photocatalysts. Characterization is performed after the synthesis of the photocatalysts to evaluate the success of the synthetic approach, but also after the completion of the evaluation of the materials in CO2 photoreduction to ensure their stability under the selected experimental parameters."@en ;
-    skos:member <http://example.org/nfdi4cat/photo/atomic-force-microscopy>,
-        <http://example.org/nfdi4cat/photo/differential-scanning-calorimetry>,
-        <http://example.org/nfdi4cat/photo/electron-energy-loss-spectroscopy>,
-        <http://example.org/nfdi4cat/photo/fourier-transform-infrared-spectroscopy>,
-        <http://example.org/nfdi4cat/photo/gas-chromatography>,
-        <http://example.org/nfdi4cat/photo/liquid-chromatography>,
-        <http://example.org/nfdi4cat/photo/mass-spectroscopy>,
-        <http://example.org/nfdi4cat/photo/nuclear-magnetic-resonance-spectroscopy>,
-        <http://example.org/nfdi4cat/photo/photoluminescence>,
-        <http://example.org/nfdi4cat/photo/raman-spectroscopy>,
-        <http://example.org/nfdi4cat/photo/scanning-electron-microscopy>,
-        <http://example.org/nfdi4cat/photo/thermogravimetric-analysis>,
-        <http://example.org/nfdi4cat/photo/transmission-electron-microscopy>,
-        <http://example.org/nfdi4cat/photo/ultraviolet-visible-spectroscopy>,
-        <http://example.org/nfdi4cat/photo/x-ray-diffraction>,
-        <http://example.org/nfdi4cat/photo/x-ray-fluorescence>,
-        <http://example.org/nfdi4cat/photo/x-ray-photoelectron-spectroscopy> ;
-    skos:prefLabel "Characterization of photocatalysts"@en .
-
-<http://example.org/nfdi4cat/photo/co2-photoreduction-measurement> a skos:Concept ;
-    dcterms:identifier "co2-photoreduction-measurement"^^xsd:token ;
+cs:0001018 a skos:Concept ;
+    dcterms:identifier "photo_0001018"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:altLabel "Carbon dioxide photoreduction measurement; Photocatalytic CO2 reduction measurement; Photocatalytic carbon dioxide reduction measurement"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/photocatalytic-co2-reduction-experiment> ;
+    skos:altLabel "Carbon dioxide photoreduction measurement"@en,
+        "Photocatalytic CO2 reduction measurement"@en,
+        "Photocatalytic carbon dioxide reduction measurement"@en ;
+    skos:broader cs:0001096 ;
     skos:definition "A single measurement of a CO2 photoreduction experiment performed either in flow or in batch mode. The measurement involves the collection of a gaseous sample, and its analysis employing an appropriate product identification method. "@en ;
     skos:inScheme cs: ;
     skos:prefLabel "CO2 photoreduction measurement"@en .
 
-<http://example.org/nfdi4cat/photo/collection-of-publications-of-interest> a skos:Concept ;
-    dcterms:identifier "collection-of-publications-of-interest"^^xsd:token ;
+cs:0001019 a skos:Concept ;
+    dcterms:identifier "photo_0001019"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/literature-research> ;
+    skos:broader cs:0001075 ;
     skos:definition "Filtering of literature research to include only the most relevant sources of information for the application / experiment / catalysts of interest."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Collection of publications of interest"@en .
 
-<http://example.org/nfdi4cat/photo/current-of-operation-of-the-light-source> a skos:Concept ;
-    dcterms:identifier "current-of-operation-of-the-light-source"^^xsd:token ;
+cs:0001023 a skos:Concept ;
+    dcterms:identifier "photo_0001023"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/light-source> ;
+    skos:broader cs:0001073 ;
     skos:definition "The value of current (usually in A or mA) used to operate the selected light source."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Current of operation of the light source"@en .
 
-<http://example.org/nfdi4cat/photo/cyclic-voltammetry> a skos:Concept ;
-    dcterms:identifier "cyclic-voltammetry"^^xsd:token ;
+cs:0001024 a skos:Concept ;
+    dcterms:identifier "photo_0001024"^^xsd:token ;
     dcterms:provenance "www.wikipedia.org"@en ;
     skos:altLabel "CV"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/characterization-of-photocatalysts> ;
+    skos:broader cs:0001013 ;
     skos:definition "A technique used to study the electrochemical properties of an analyte in solution or of a molecule that is adsorbed onto the electrode. In a cyclic voltammetry experiment, the working electrode potential is ramped linearly versus time. The current at the working electrode us plotted versus the applied voltage to give the cyclic votammogram trace."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Cyclic Voltammetry"@en .
 
-<http://example.org/nfdi4cat/photo/diameter-of-optical-window> a skos:Concept ;
-    dcterms:identifier "diameter-of-optical-window"^^xsd:token ;
+cs:0001027 a skos:Concept ;
+    dcterms:identifier "photo_0001027"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:altLabel "Diameter of window; Window diameter"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/dimensions-of-optical-window> ;
+    skos:altLabel "Diameter of window"@en,
+        "Window diameter"@en ;
+    skos:broader cs:0001031 ;
     skos:definition "Diameter of the optical window allowing the incoming light to enter the reaction chamber and interact with the photocatalyst."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Diameter of optical window"@en .
 
-<http://example.org/nfdi4cat/photo/dielectric-barrier-discharge-ionization-detector> a skos:Concept ;
-    dcterms:identifier "dielectric-barrier-discharge-ionization-detector"^^xsd:token ;
+cs:0001028 a skos:Concept ;
+    dcterms:identifier "photo_0001028"^^xsd:token ;
     dcterms:provenance "Self"@en ;
     skos:altLabel "BID"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/equipped-detectors-of-gas-chromatograph> ;
+    skos:broader cs:0001045 ;
     skos:definition "Detector incorporating Ionization via a new dielectric barrier discharge He plasma."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Dielectric-Barrier Discharge Ionization Detector"@en .
 
-<http://example.org/nfdi4cat/photo/dimensions-of-reaction-chamber> a skos:Concept ;
-    dcterms:identifier "dimensions-of-reaction-chamber"^^xsd:token ;
+cs:0001032 a skos:Concept ;
+    dcterms:identifier "photo_0001032"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/reaction-chamber> ;
+    skos:broader cs:0001115 ;
     skos:definition "Height, width and depth (in cubic- or rectangular- shaped reaction chambers) or diameter and height (in cylindrer - shaped reaction chambers)"@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Dimensions of reaction chamber"@en .
 
-<http://example.org/nfdi4cat/photo/dimensions-of-substrate> a skos:Concept ;
-    dcterms:identifier "dimensions-of-substrate"^^xsd:token ;
+cs:0001033 a skos:Concept ;
+    dcterms:identifier "photo_0001033"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/substrate> ;
+    skos:broader cs:0001132 ;
     skos:definition "The diamensions (area / thickness / diameter) of the substrate."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Dimensions of substrate"@en .
 
-<http://example.org/nfdi4cat/photo/distance-of-light-source-from-the-reaction-chamber-sample> a skos:Concept ;
-    dcterms:identifier "distance-of-light-source-from-the-reaction-chamber-sample"^^xsd:token ;
+cs:0001034 a skos:Concept ;
+    dcterms:identifier "photo_0001034"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/light-source> ;
+    skos:broader cs:0001073 ;
     skos:definition "The distance of the light source from the reaction chamber and the photocatalyst."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Distance of light source from the reaction chamber / sample "@en .
 
-<http://example.org/nfdi4cat/photo/doctor-blading> a skos:Concept ;
-    dcterms:identifier "doctor-blading"^^xsd:token ;
+cs:0001035 a skos:Concept ;
+    dcterms:identifier "photo_0001035"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/deposition-technique> ;
+    skos:broader cs:0001026 ;
     skos:definition "A tape-casting method used to deposit thin films of a photocatalyst onto the surface of a substrate."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Doctor blading"@en .
 
-<http://example.org/nfdi4cat/photo/duration-of-steps> a skos:Concept ;
-    dcterms:identifier "duration-of-steps"^^xsd:token ;
+cs:0001037 a skos:Concept ;
+    dcterms:identifier "photo_0001037"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/synthesis-steps> ;
+    skos:broader cs:0001134 ;
     skos:definition "Duration of each synthesis step needed to synthesize the desired photocatalyst."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Duration of steps"@en .
 
-<http://example.org/nfdi4cat/photo/dwelling-time> a skos:Concept ;
-    dcterms:identifier "dwelling-time"^^xsd:token ;
+cs:0001038 a skos:Concept ;
+    dcterms:identifier "photo_0001038"^^xsd:token ;
     dcterms:provenance "Self"@en ;
     skos:altLabel "Soaking time"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/calcination-steps> ;
+    skos:broader cs:0001009 ;
     skos:definition "Time (usually in h) for which a desired temperature is held."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Dwelling time"@en .
 
-<http://example.org/nfdi4cat/photo/equipment-for-controlling-and-monitoring-operation-temperature> a skos:Concept ;
-    dcterms:identifier "equipment-for-controlling-and-monitoring-operation-temperature"^^xsd:token ;
+cs:0001043 a skos:Concept ;
+    dcterms:identifier "photo_0001043"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:altLabel "Temperature controller; Temperature gauge; Temperature monitor; Heating device; Cooling device"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/range-of-operation-temperature> ;
+    skos:altLabel "Cooling device"@en,
+        "Heating device"@en,
+        "Temperature controller"@en,
+        "Temperature gauge"@en,
+        "Temperature monitor"@en ;
+    skos:broader cs:0001113 ;
     skos:definition "Equipment used for controlling and/or monitoring the temperature in various parts of a photoreactor. This can include hot plates, heating elements and cryostats. Light sources in operation can also affect the temperature in the reaction chamber."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Equipment for controlling and monitoring operation temperature"@en .
 
-<http://example.org/nfdi4cat/photo/equipment-used-for-synthesis> a skos:Concept ;
-    dcterms:identifier "equipment-used-for-synthesis"^^xsd:token ;
+cs:0001044 a skos:Concept ;
+    dcterms:identifier "photo_0001044"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/synthesis-steps> ;
+    skos:broader cs:0001134 ;
     skos:definition "Equipment used in each step of the synthesis of the photocatalysts. The equipment can incude (but not limited to): crucibles, pH meters, condensers, volumetric cylinders, centrifuges, test tubes, flasks, beakers, mechanical shakers, pipettes, syringes, magenetic stirrers, heating plates, fitlers, funnels and digital balances."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Equipment used for synthesis"@en .
 
-<http://example.org/nfdi4cat/photo/equipped-detectors-of-mass-spectrometer> a skos:Concept ;
-    dcterms:identifier "equipped-detectors-of-mass-spectrometer"^^xsd:token ;
+cs:0001046 a skos:Concept ;
+    dcterms:identifier "photo_0001046"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/mass-spectrometry> ;
+    skos:broader cs:0001080 ;
     skos:definition "Detectors of the mass spectrometer used to identify the reaction products and intemediates."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Equipped detectors of mass spectrometer"@en .
 
-<http://example.org/nfdi4cat/photo/evaluation-of-performance-coll> a skos:Collection ;
-    dcterms:identifier "evaluation-of-performance-coll"^^xsd:token ;
-    dcterms:isPartOf cs: ;
-    dcterms:provenance "Self"@en ;
-    skos:definition "Selection of experimental parameters applied for the evaluation of the performance of a photocatalyst in CO2 photoreduction."@en ;
-    skos:member <http://example.org/nfdi4cat/photo/concentration-of-reactants>,
-        <http://example.org/nfdi4cat/photo/form-of-photocatalyst>,
-        <http://example.org/nfdi4cat/photo/irradiation-time>,
-        <http://example.org/nfdi4cat/photo/light-source>,
-        <http://example.org/nfdi4cat/photo/operation-mode>,
-        <http://example.org/nfdi4cat/photo/purity-of-reactants>,
-        <http://example.org/nfdi4cat/photo/sampling-intervals>,
-        <http://example.org/nfdi4cat/photo/total-duration-of-experiment> ;
-    skos:prefLabel "Evaluation of performance"@en .
-
-<http://example.org/nfdi4cat/photo/evaluation-of-products-formed> a skos:Concept ;
-    dcterms:identifier "evaluation-of-products-formed"^^xsd:token ;
+cs:0001048 a skos:Concept ;
+    dcterms:identifier "photo_0001048"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/photocatalytic-co2-reduction-experiment> ;
+    skos:broader cs:0001096 ;
     skos:definition "Calculation of the concentration of the products formed in a CO2 photoreduction experiment. "@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Evaluation of products formed"@en .
 
-<http://example.org/nfdi4cat/photo/final-temperature> a skos:Concept ;
-    dcterms:identifier "final-temperature"^^xsd:token ;
+cs:0001051 a skos:Concept ;
+    dcterms:identifier "photo_0001051"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/calcination-steps> ;
+    skos:broader cs:0001009 ;
     skos:definition "Final temperature of the calcination step."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Final temperature"@en .
 
-<http://example.org/nfdi4cat/photo/flame-ionization-detector> a skos:Concept ;
-    dcterms:identifier "flame-ionization-detector"^^xsd:token ;
+cs:0001052 a skos:Concept ;
+    dcterms:identifier "photo_0001052"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
     skos:altLabel "FID"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/equipped-detectors-of-gas-chromatograph> ;
+    skos:broader cs:0001045 ;
     skos:definition "The gases emerging from the column are fed into a hydrogen flame across which an electrical potential is placed. Certain molecules ionize easily in the flame and the current produced is proportional to the instantaneous flow rate of the eluted component. The detector is relatively insensitive to inorganic molecules and is most used for organic compounds. Concentrations below 1 ppmv are easily detected. The linear dynamic range is between 10E3 and 10E5."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Flame Ionization Detector"@en .
 
-<http://example.org/nfdi4cat/photo/flow-mode> a skos:Concept ;
-    dcterms:identifier "flow-mode"^^xsd:token ;
+cs:0001053 a skos:Concept ;
+    dcterms:identifier "photo_0001053"^^xsd:token ;
     dcterms:provenance "Self"@en ;
     skos:altLabel "Continuous flow mode"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/operation-mode> ;
+    skos:broader cs:0001089 ;
     skos:definition "A mode under which the CO2 photoreduction experiment is performed. Under flow conditions, a continuous flow of reactants is supplied to the reaction chamber and the formed products are removed and identified by an appropriate technique."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Flow mode"@en .
 
-<http://example.org/nfdi4cat/photo/flow-mode-co2-reduction-experiment> a skos:Concept ;
-    dcterms:identifier "flow-mode-co2-reduction-experiment"^^xsd:token ;
+cs:0001054 a skos:Concept ;
+    dcterms:identifier "photo_0001054"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:definition "A mode under which the CO2 photoreduction experiment is performed. Under flow conditions, a continuous flow of reactants is supplied to the reaction chamber and the formed products are removed and identified by an appropriate technique."@en ;
-    skos:inScheme cs: ;
-    skos:prefLabel "Flow mode CO2 reduction experiment"@en ;
-    skos:topConceptOf cs: .
-
-<http://example.org/nfdi4cat/photo/flow-rate-of-gas-used-for-calcination> a skos:Concept ;
-    dcterms:identifier "flow-rate-of-gas-used-for-calcination"^^xsd:token ;
-    dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/gaseous-environment> ;
+    skos:broader cs:0001060 ;
     skos:definition "The flow of gas (usually in ml min-1) used in the calcination steps during synthesis"@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Flow rate of gas used for calcination"@en .
 
-<http://example.org/nfdi4cat/photo/flow-rates-of-reactants> a skos:Concept ;
-    dcterms:identifier "flow-rates-of-reactants"^^xsd:token ;
+cs:0001055 a skos:Concept ;
+    dcterms:identifier "photo_0001055"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/reactants> ;
+    skos:broader cs:0001114 ;
     skos:definition "The rate of flow of reactants (often in ml per min) in the photoreactor. Flow rates are usually controlled by mass flow controllers (MFCs)  "@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Flow rates of reactants"@en .
 
-<http://example.org/nfdi4cat/photo/fluorine-doped-tin-oxide-coated-glass> a skos:Concept ;
-    dcterms:identifier "fluorine-doped-tin-oxide-coated-glass"^^xsd:token ;
+cs:0001056 a skos:Concept ;
+    dcterms:identifier "photo_0001056"^^xsd:token ;
     dcterms:provenance "Self"@en ;
     skos:altLabel "FTO glass"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/glass-substrate> ;
+    skos:broader cs:0001063 ;
     skos:definition "Transparent conductive metal oxide (fluorine doped tin oxide) that can be used in the fabrication of transparent electrodes for thin films"@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Fluorine doped tin oxide coated glass"@en .
 
-<http://example.org/nfdi4cat/photo/general-terms-coll> a skos:Collection ;
-    dcterms:identifier "general-terms-coll"^^xsd:token ;
-    dcterms:isPartOf cs: ;
-    dcterms:provenance "Self"@en ;
-    skos:definition "General terms often used in the field of photocatalysis."@en ;
-    skos:member <http://example.org/nfdi4cat/photo/absorption>,
-        <http://example.org/nfdi4cat/photo/bandgap-energy>,
-        <http://example.org/nfdi4cat/photo/charge-photogeneration>,
-        <http://example.org/nfdi4cat/photo/charge-recombination>,
-        <http://example.org/nfdi4cat/photo/charge-separation>,
-        <http://example.org/nfdi4cat/photo/conduction-band>,
-        <http://example.org/nfdi4cat/photo/crystallinity>,
-        <http://example.org/nfdi4cat/photo/doping>,
-        <http://example.org/nfdi4cat/photo/electron-transfer>,
-        <http://example.org/nfdi4cat/photo/excited-state>,
-        <http://example.org/nfdi4cat/photo/fermi-level>,
-        <http://example.org/nfdi4cat/photo/ground-state>,
-        <http://example.org/nfdi4cat/photo/hole-transfer>,
-        <http://example.org/nfdi4cat/photo/infrared>,
-        <http://example.org/nfdi4cat/photo/metal-oxide>,
-        <http://example.org/nfdi4cat/photo/oxidation>,
-        <http://example.org/nfdi4cat/photo/photocatalyst>,
-        <http://example.org/nfdi4cat/photo/photoexcitation>,
-        <http://example.org/nfdi4cat/photo/pore-size-distribution>,
-        <http://example.org/nfdi4cat/photo/reduction>,
-        <http://example.org/nfdi4cat/photo/semiconductor>,
-        <http://example.org/nfdi4cat/photo/specific-surface-area>,
-        <http://example.org/nfdi4cat/photo/ultraviolet>,
-        <http://example.org/nfdi4cat/photo/valence-band>,
-        <http://example.org/nfdi4cat/photo/visible>,
-        <http://example.org/nfdi4cat/photo/wavelength> ;
-    skos:prefLabel "General terms"@en .
-
-<http://example.org/nfdi4cat/photo/heating-rate> a skos:Concept ;
-    dcterms:identifier "heating-rate"^^xsd:token ;
+cs:0001065 a skos:Concept ;
+    dcterms:identifier "photo_0001065"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/calcination-steps> ;
+    skos:broader cs:0001009 ;
     skos:definition "Rate of increasing or decreasing the temperature during the calcination step. Usually mentioned in K min-1."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Heating rate"@en .
 
-<http://example.org/nfdi4cat/photo/indium-tin-oxide-coated-glass> a skos:Concept ;
-    dcterms:identifier "indium-tin-oxide-coated-glass"^^xsd:token ;
+cs:0001067 a skos:Concept ;
+    dcterms:identifier "photo_0001067"^^xsd:token ;
     dcterms:provenance "Self"@en ;
     skos:altLabel "ITO glass"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/glass-substrate> ;
+    skos:broader cs:0001063 ;
     skos:definition "Transparent conductive metal oxide (indium tin oxide) that can be used in the fabrication of transparent electrodes for thin films"@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Indium tin oxide coated glass"@en .
 
-<http://example.org/nfdi4cat/photo/initial-temperature> a skos:Concept ;
-    dcterms:identifier "initial-temperature"^^xsd:token ;
+cs:0001069 a skos:Concept ;
+    dcterms:identifier "photo_0001069"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/calcination-steps> ;
+    skos:broader cs:0001009 ;
     skos:definition "Initial temperature of the calcination step."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Initial temperature"@en .
 
-<http://example.org/nfdi4cat/photo/intensity-of-the-light-source> a skos:Concept ;
-    dcterms:identifier "intensity-of-the-light-source"^^xsd:token ;
+cs:0001070 a skos:Concept ;
+    dcterms:identifier "photo_0001070"^^xsd:token ;
     dcterms:provenance "Self"@en ;
     skos:altLabel "Light intensity"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/light-source> ;
+    skos:broader cs:0001073 ;
     skos:definition "The light intensity (usually in mW cm-2) of the selected light source. The light intensity should be measured at the same distance as the one between the light source and the reaction chamber / sample."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Intensity of the light source"@en .
 
-<http://example.org/nfdi4cat/photo/light-intensity> a skos:Concept ;
-    dcterms:identifier "light-intensity"^^xsd:token ;
+cs:0001072 a skos:Concept ;
+    dcterms:identifier "photo_0001072"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/selected-light-source> ;
+    skos:broader cs:0001123 ;
     skos:definition "The value of intensity of light emitted by the selected light source. The light intensity must be measured at the same distance as the light source from the reaction chamber / sample. "@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Light intensity"@en .
 
-<http://example.org/nfdi4cat/photo/mass-flow-controller> a skos:Concept ;
-    dcterms:identifier "mass-flow-controller"^^xsd:token ;
+cs:0001076 a skos:Concept ;
+    dcterms:identifier "photo_0001076"^^xsd:token ;
+    dcterms:provenance "Self"@en ;
+    skos:broader cs:0001017 ;
+    skos:definition "Masses / volumes / concentrations of chemicals used for synthesis"@en ;
+    skos:inScheme cs: ;
+    skos:prefLabel "Masses / volumes / concentrations of chemicals used in synthesis"@en .
+
+cs:0001077 a skos:Concept ;
+    dcterms:identifier "photo_0001077"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:altLabel "MFC; MFCs"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/equipment-controlling-and-monitoring-gas-flow> ;
+    skos:altLabel "MFC"@en,
+        "MFCs"@en ;
+    skos:broader cs:0001041 ;
     skos:definition "Devices used to control and monitor gas or liquid flow rates."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Mass flow controller"@en .
 
-<http://example.org/nfdi4cat/photo/mass-of-deposited-film> a skos:Concept ;
-    dcterms:identifier "mass-of-deposited-film"^^xsd:token ;
+cs:0001078 a skos:Concept ;
+    dcterms:identifier "photo_0001078"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/deposited-film> ;
+    skos:broader cs:0001025 ;
     skos:definition "Mass of material deposited onto the surface of a substrate."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Mass of deposited film"@en .
 
-<http://example.org/nfdi4cat/photo/mass-of-powder-used> a skos:Concept ;
-    dcterms:identifier "mass-of-powder-used"^^xsd:token ;
+cs:0001079 a skos:Concept ;
+    dcterms:identifier "photo_0001079"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/powdered-photocatalyst> ;
+    skos:broader cs:0001101 ;
     skos:definition "Mass of a powdered photocatalyst used for a CO2 photoreduction experiment."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Mass of powder used"@en .
 
-<http://example.org/nfdi4cat/photo/masses-volumes-concentrations-of-chemicals-used-in-synthesis> a skos:Concept ;
-    dcterms:identifier "masses-volumes-concentrations-of-chemicals-used-in-synthesis"^^xsd:token ;
+cs:0001082 a skos:Concept ;
+    dcterms:identifier "photo_0001082"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/chemical-substances-used-for-synthesis> ;
-    skos:definition "Masses / volumes / concentrations of chemicals used for synthesis"@en ;
-    skos:inScheme cs: ;
-    skos:prefLabel "Masses / volumes / concentrations of chemicals used in synthesis"@en .
-
-<http://example.org/nfdi4cat/photo/material-of-optical-window> a skos:Concept ;
-    dcterms:identifier "material-of-optical-window"^^xsd:token ;
-    dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/optical-window> ;
+    skos:broader cs:0001090 ;
     skos:definition "Material that the window is made of. The window, usually attached to the lid sealing the reaction chamber, allows for the incoming light to enter the reaction chamber and interact with the photocatalyst. The material of the window influences the wavelenth range the the photocatalyst experieneces. "@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Material of optical window"@en .
 
-<http://example.org/nfdi4cat/photo/material-of-reaction-chamber> a skos:Concept ;
-    dcterms:identifier "material-of-reaction-chamber"^^xsd:token ;
+cs:0001083 a skos:Concept ;
+    dcterms:identifier "photo_0001083"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/reaction-chamber> ;
+    skos:broader cs:0001115 ;
     skos:definition "Material used for the construction of the main body of the reaction chamber."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Material of reaction chamber"@en .
 
-<http://example.org/nfdi4cat/photo/metallic-substrate> a skos:Concept ;
-    dcterms:identifier "metallic-substrate"^^xsd:token ;
+cs:0001085 a skos:Concept ;
+    dcterms:identifier "photo_0001085"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/material-of-substrate> ;
+    skos:broader cs:0001084 ;
     skos:definition "A  flat surface made of a metal (e.g., titanium, stainless steel) serving as a substrate for the deposition of a photocatalyst."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Metallic substrate"@en .
 
-<http://example.org/nfdi4cat/photo/mott-schottky-analysis> a skos:Concept ;
-    dcterms:identifier "mott-schottky-analysis"^^xsd:token ;
+cs:0001087 a skos:Concept ;
+    dcterms:identifier "photo_0001087"^^xsd:token ;
     dcterms:provenance "www.wikipedia.org"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/characterization-of-photocatalysts> ;
+    skos:broader cs:0001013 ;
     skos:definition "In semiconductor electrochemistry, a Mott-Schottky plot describes the reciprocal of the square of capacitance versus the potential difference between bulk semincoductor and bulk electrolyte. A Mott-Schottky analysis is used to determine system properties such as: flatband potential, doping density, Helmholtz capacitance, position of conduction and valence band."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Mott-Schottky analysis"@en .
 
-<http://example.org/nfdi4cat/photo/organization-of-literature-in-a-citation-management-software> a skos:Concept ;
-    dcterms:identifier "organization-of-literature-in-a-citation-management-software"^^xsd:token ;
+cs:0001091 a skos:Concept ;
+    dcterms:identifier "photo_0001091"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:altLabel "Literature organization; Organization of literature; Citation management software"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/literature-research> ;
+    skos:altLabel "Citation management software"@en,
+        "Literature organization"@en,
+        "Organization of literature"@en ;
+    skos:broader cs:0001075 ;
     skos:definition "Addition and organization of relevant literature of interest using a citation management software (e.g., Mendeley, Zotero, EndNote etc.) allowing for easy access and categorization."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Organization of literature in a citation management software"@en .
 
-<http://example.org/nfdi4cat/photo/ph-in-synthesis> a skos:Concept ;
-    dcterms:identifier "ph-in-synthesis"^^xsd:token ;
+cs:0001093 a skos:Concept ;
+    dcterms:identifier "photo_0001093"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/synthesis-steps> ;
+    skos:broader cs:0001134 ;
     skos:definition "pH value in each of the synthesis steps (if applicable)"@en ;
     skos:inScheme cs: ;
     skos:prefLabel "pH in synthesis"@en .
 
-<http://example.org/nfdi4cat/photo/photocatalytic-co2-reduction-coll> a skos:Collection ;
-    dcterms:identifier "photocatalytic-co2-reduction-coll"^^xsd:token ;
-    dcterms:isPartOf cs: ;
+cs:0001102 a skos:Concept ;
+    dcterms:identifier "photo_0001102"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:definition "The light-driven reduction (conversion) of carbon dioxide (CO2) to hydrocarbons and / or platform chemicals in presence of water. The absorption of light and the adsorption of the reactants is performed by a photocatalyst (usually a metal oxide). "@en ;
-    skos:member <http://example.org/nfdi4cat/photo/characterization-of-photocatalysts>,
-        <http://example.org/nfdi4cat/photo/evaluation-of-performance>,
-        <http://example.org/nfdi4cat/photo/photoreactor-design>,
-        <http://example.org/nfdi4cat/photo/synthesis-of-photocatalysts> ;
-    skos:prefLabel "Photocatalytic CO2 reduction"@en .
-
-<http://example.org/nfdi4cat/photo/power-output-of-the-light-source> a skos:Concept ;
-    dcterms:identifier "power-output-of-the-light-source"^^xsd:token ;
-    dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/light-source> ;
+    skos:broader cs:0001073 ;
     skos:definition "The power of the light source (usually in W or mW). The power can be calculated by the multiplication of the current and voltage used to operate the light source,"@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Power output of the light source"@en .
 
-<http://example.org/nfdi4cat/photo/pressure-drop> a skos:Concept ;
-    dcterms:identifier "pressure-drop"^^xsd:token ;
+cs:0001103 a skos:Concept ;
+    dcterms:identifier "photo_0001103"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/pressure-drop-in-a-co2-phoreduction-experiment> ;
+    skos:broader cs:0001104 ;
     skos:definition "todo"@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Pressure drop"@en .
 
-<http://example.org/nfdi4cat/photo/pressure-in-a-co2-photoreduction-experiment> a skos:Concept ;
-    dcterms:identifier "pressure-in-a-co2-photoreduction-experiment"^^xsd:token ;
+cs:0001105 a skos:Concept ;
+    dcterms:identifier "photo_0001105"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/photocatalytic-co2-reduction-experiment> ;
+    skos:broader cs:0001096 ;
     skos:definition "The pressure (range) under which the CO2 photoreduction takes place."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Pressure in a CO2 photoreduction experiment"@en .
 
-<http://example.org/nfdi4cat/photo/pressure-in-synthesis> a skos:Concept ;
-    dcterms:identifier "pressure-in-synthesis"^^xsd:token ;
+cs:0001106 a skos:Concept ;
+    dcterms:identifier "photo_0001106"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/synthesis-steps> ;
+    skos:broader cs:0001134 ;
     skos:definition "Pressure applied (if necessary) in any of the synthesis step. Changes in the pressure may be observed if variations in the temperature of the reaction occur (e.g., exothermic reaction) "@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Pressure in synthesis"@en .
 
-<http://example.org/nfdi4cat/photo/purging-time> a skos:Concept ;
-    dcterms:identifier "purging-time"^^xsd:token ;
+cs:0001108 a skos:Concept ;
+    dcterms:identifier "photo_0001108"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/total-duration-of-experiment> ;
+    skos:broader cs:0001142 ;
     skos:definition "Time for which a gas is purged through the reaction chamber."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Purging time"@en .
 
-<http://example.org/nfdi4cat/photo/quartz-glass> a skos:Concept ;
-    dcterms:identifier "quartz-glass"^^xsd:token ;
+cs:0001110 a skos:Concept ;
+    dcterms:identifier "photo_0001110"^^xsd:token ;
     dcterms:provenance "https://www.collinsdictionary.com/"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/glass-substrate> ;
+    skos:broader cs:0001063 ;
     skos:definition "A colourless glass composed of almost pure silica, resistant to very high temperatures and transparent to near-ultraviolet radiation"@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Quartz glass"@en .
 
-<http://example.org/nfdi4cat/photo/reactor-design-coll> a skos:Collection ;
-    dcterms:identifier "reactor-design-coll"^^xsd:token ;
-    dcterms:isPartOf cs: ;
-    dcterms:provenance "Self"@en ;
-    skos:definition "Details describing the construction, physical dimensions, and operation of the photoreactor used for the photocalytic CO2 reduction reactions."@en ;
-    skos:member <http://example.org/nfdi4cat/photo/gas-flow>,
-        <http://example.org/nfdi4cat/photo/light-source>,
-        <http://example.org/nfdi4cat/photo/operation-mode>,
-        <http://example.org/nfdi4cat/photo/product-identification-method>,
-        <http://example.org/nfdi4cat/photo/range-of-operation-pressure>,
-        <http://example.org/nfdi4cat/photo/range-of-operation-temperature>,
-        <http://example.org/nfdi4cat/photo/reaction-chamber> ;
-    skos:prefLabel "Reactor design"@en .
-
-<http://example.org/nfdi4cat/photo/sacrificial-acceptor> a skos:Concept ;
-    dcterms:identifier "sacrificial-acceptor"^^xsd:token ;
+cs:0001117 a skos:Concept ;
+    dcterms:identifier "photo_0001117"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/sacrificial-reagents> ;
+    skos:broader cs:0001119 ;
     skos:definition "Molecular entity that acts as the electron acceptor in a photoinduced electron transfer process and is not restored in a subsequent oxidation process but is destroyed by irreversible chemical conversion."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Sacrificial acceptor"@en .
 
-<http://example.org/nfdi4cat/photo/sacrificial-donor> a skos:Concept ;
-    dcterms:identifier "sacrificial-donor"^^xsd:token ;
+cs:0001118 a skos:Concept ;
+    dcterms:identifier "photo_0001118"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/sacrificial-reagents> ;
+    skos:broader cs:0001119 ;
     skos:definition "Molecular entity that acts as the electron donor in a photoinduced electron transfer process and is not restored in a subsequent reduction process but is destroyed by the irreversible chemical conversion."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Sacrificial donor"@en .
 
-<http://example.org/nfdi4cat/photo/sample-pre-treatment> a skos:Concept ;
-    dcterms:identifier "sample-pre-treatment"^^xsd:token ;
+cs:0001120 a skos:Concept ;
+    dcterms:identifier "photo_0001120"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/photocatalytic-co2-reduction-experiment> ;
+    skos:broader cs:0001096 ;
     skos:definition "Pretreatment of the photocatalyst before its intoduction to the reaction chamber."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Sample pre-treatment"@en .
 
-<http://example.org/nfdi4cat/photo/selectivity> a skos:Concept ;
-    dcterms:identifier "selectivity"^^xsd:token ;
+cs:0001124 a skos:Concept ;
+    dcterms:identifier "photo_0001124"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/photocatalytic-co2-reduction-experiment> ;
+    skos:broader cs:0001096 ;
     skos:definition "Identification of the mixture of gaseous products in a CO2 photoreduction experiment. "@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Selectivity"@en .
 
-<http://example.org/nfdi4cat/photo/sensitivity-of-gas-chromatograph> a skos:Concept ;
-    dcterms:identifier "sensitivity-of-gas-chromatograph"^^xsd:token ;
+cs:0001126 a skos:Concept ;
+    dcterms:identifier "photo_0001126"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/gas-chromatography> ;
+    skos:broader cs:0001059 ;
     skos:definition "The minimum concentration of a product or intermediate that the gas chromatograph can identify. "@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Sensitivity of gas chromatograph"@en .
 
-<http://example.org/nfdi4cat/photo/sensitivity-of-mass-spectrometer> a skos:Concept ;
-    dcterms:identifier "sensitivity-of-mass-spectrometer"^^xsd:token ;
+cs:0001127 a skos:Concept ;
+    dcterms:identifier "photo_0001127"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/mass-spectrometry> ;
+    skos:broader cs:0001080 ;
     skos:definition "The minimum concentration of a product or intermediate that the mass spectrometer can identify. "@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Sensitivity of mass spectrometer"@en .
 
-<http://example.org/nfdi4cat/photo/shape-of-reaction-chamber> a skos:Concept ;
-    dcterms:identifier "shape-of-reaction-chamber"^^xsd:token ;
+cs:0001128 a skos:Concept ;
+    dcterms:identifier "photo_0001128"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/reaction-chamber> ;
+    skos:broader cs:0001115 ;
     skos:definition "The shape of the reaction chamber. In gas-phase CO2 photoreduction, reaction chambers have usually a cylindrical, cubical or rectangular shape."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Shape of reaction chamber"@en .
 
-<http://example.org/nfdi4cat/photo/spin-coating> a skos:Concept ;
-    dcterms:identifier "spin-coating"^^xsd:token ;
+cs:0001130 a skos:Concept ;
+    dcterms:identifier "photo_0001130"^^xsd:token ;
     dcterms:provenance "www.wikipedia.org"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/deposition-technique> ;
+    skos:broader cs:0001026 ;
     skos:definition "Spin coating is a procedure used to deposit uniform thin films onto flat substrates. Usually a small amount of coating material is applied on the center of the substrate, which is either spinning at low speed or not spinning at all. The substrate is then rotated at speed up to 10,000 rpm to spread the coating material by centrifugal force."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Spin coating"@en .
 
-<http://example.org/nfdi4cat/photo/spray-coating> a skos:Concept ;
-    dcterms:identifier "spray-coating"^^xsd:token ;
+cs:0001131 a skos:Concept ;
+    dcterms:identifier "photo_0001131"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/deposition-technique> ;
+    skos:broader cs:0001026 ;
     skos:definition "A technique in which a solution containing the photocatalyst, is forced through a nozzle whereby a fine aerosol will be formed. This aerosol is sprayed on the surface of an appropriate substrate."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Spray coating"@en .
 
-<http://example.org/nfdi4cat/photo/synthesis-of-photocatalysts-coll> a skos:Collection ;
-    dcterms:identifier "synthesis-of-photocatalysts-coll"^^xsd:token ;
-    dcterms:isPartOf cs: ;
-    dcterms:provenance "Self"@en ;
-    skos:definition "The process by which one or more chemical reactions are performed with the aim of converting a reactant or starting material into a product or multiple products."@en ;
-    skos:member <http://example.org/nfdi4cat/photo/chemical-substances-used-for-synthesis>,
-        <http://example.org/nfdi4cat/photo/literature-research>,
-        <http://example.org/nfdi4cat/photo/synthesis-steps> ;
-    skos:prefLabel "Synthesis of photocatalysts"@en .
-
-<http://example.org/nfdi4cat/photo/temperature-in-a-co2-photoreduction-experiment> a skos:Concept ;
-    dcterms:identifier "temperature-in-a-co2-photoreduction-experiment"^^xsd:token ;
+cs:0001135 a skos:Concept ;
+    dcterms:identifier "photo_0001135"^^xsd:token ;
     dcterms:provenance "Self"@en ;
     skos:definition "The temperature (range) under which the CO2 photoreduction takes place."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Temperature in a CO2 photoreduction experiment"@en ;
     skos:topConceptOf cs: .
 
-<http://example.org/nfdi4cat/photo/temperature-in-synthesis> a skos:Concept ;
-    dcterms:identifier "temperature-in-synthesis"^^xsd:token ;
+cs:0001136 a skos:Concept ;
+    dcterms:identifier "photo_0001136"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/synthesis-steps> ;
+    skos:broader cs:0001134 ;
     skos:definition "Temperature externally applied (if necessary) in any of the synthesis step. Higher temperature values can be observed if an exothermic reaction takes place during the synthesis."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Temperature in synthesis"@en .
 
-<http://example.org/nfdi4cat/photo/thermal-conductivity-detector> a skos:Concept ;
-    dcterms:identifier "thermal-conductivity-detector"^^xsd:token ;
+cs:0001137 a skos:Concept ;
+    dcterms:identifier "photo_0001137"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
     skos:altLabel "TCD"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/equipped-detectors-of-gas-chromatograph> ;
+    skos:broader cs:0001045 ;
     skos:definition """
 In general, two cells arranged in a bridge configuration detect the change in thermal conductivity of the gas at the output of the column. This detector is sensitive to any substance with thermal conductivity different from that of the carrier gas. The lowest detectable limit is between 0.5 and 100 ppmv. The linear dynamic range is of the order of 103. This type of detector is often used for measuring components at relatively high concentrations."""@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Thermal conductivity detector"@en .
 
-<http://example.org/nfdi4cat/photo/thickness-of-deposited-film> a skos:Concept ;
-    dcterms:identifier "thickness-of-deposited-film"^^xsd:token ;
+cs:0001139 a skos:Concept ;
+    dcterms:identifier "photo_0001139"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/dimensions-of-deposited-film> ;
+    skos:broader cs:0001030 ;
     skos:definition "The thickness of the film of the deposited photocatalyst. "@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Thickness of deposited film"@en .
 
-<http://example.org/nfdi4cat/photo/thickness-of-optical-window> a skos:Concept ;
-    dcterms:identifier "thickness-of-optical-window"^^xsd:token ;
+cs:0001140 a skos:Concept ;
+    dcterms:identifier "photo_0001140"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:altLabel "Thickness of window; Window thickness"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/dimensions-of-optical-window> ;
+    skos:altLabel "Thickness of window"@en,
+        "Window thickness"@en ;
+    skos:broader cs:0001031 ;
     skos:definition "Thickness of the optical window allowing the incoming light to enter the reaction chamber and interact with the photocatalyst."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Thickness of optical window"@en .
 
-<http://example.org/nfdi4cat/photo/vacuum-pump> a skos:Concept ;
-    dcterms:identifier "vacuum-pump"^^xsd:token ;
+cs:0001146 a skos:Concept ;
+    dcterms:identifier "photo_0001146"^^xsd:token ;
     dcterms:provenance "https://www.merriam-webster.com"@en ;
     skos:altLabel "Pump"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/equipment-for-controlling-and-monitoring-operation-pressure> ;
+    skos:broader cs:0001042 ;
     skos:definition "A pump for exhausting gas from an enclosed space"@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Vacuum pump"@en .
 
-<http://example.org/nfdi4cat/photo/voltage-of-operation-of-the-light-source> a skos:Concept ;
-    dcterms:identifier "voltage-of-operation-of-the-light-source"^^xsd:token ;
+cs:0001149 a skos:Concept ;
+    dcterms:identifier "photo_0001149"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/light-source> ;
+    skos:broader cs:0001073 ;
     skos:definition "The value of voltage  (usually in V or mV) used to operate the selected light source."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Voltage of operation of the light source"@en .
 
-<http://example.org/nfdi4cat/photo/volume-of-the-reaction-chamber> a skos:Concept ;
-    dcterms:identifier "volume-of-the-reaction-chamber"^^xsd:token ;
+cs:0001150 a skos:Concept ;
+    dcterms:identifier "photo_0001150"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/reaction-chamber> ;
+    skos:broader cs:0001115 ;
     skos:definition "Volume of the reaction chamber, calculated by its dimensions. Volume of pipes and valves connected to the reaction chamber should also be calculated and added to the total volume. "@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Volume of the reaction chamber"@en .
 
-<http://example.org/nfdi4cat/photo/absorption> a skos:Concept ;
-    dcterms:identifier "absorption"^^xsd:token ;
+cs:0001156 a skos:Collection ;
+    dcterms:identifier "photo_0001156"^^xsd:token ;
+    dcterms:isPartOf cs: ;
+    dcterms:provenance "Self"@en ;
+    skos:definition "General terms often used in the field of photocatalysis."@en ;
+    skos:member cs:0001001,
+        cs:0001004,
+        cs:0001014,
+        cs:0001015,
+        cs:0001016,
+        cs:0001021,
+        cs:0001022,
+        cs:0001036,
+        cs:0001040,
+        cs:0001049,
+        cs:0001050,
+        cs:0001064,
+        cs:0001066,
+        cs:0001068,
+        cs:0001086,
+        cs:0001092,
+        cs:0001094,
+        cs:0001097,
+        cs:0001100,
+        cs:0001116,
+        cs:0001125,
+        cs:0001129,
+        cs:0001144,
+        cs:0001147,
+        cs:0001148,
+        cs:0001151 ;
+    skos:prefLabel "General terms"@en .
+
+cs:0001157 a skos:Collection ;
+    dcterms:identifier "photo_0001157"^^xsd:token ;
+    dcterms:isPartOf cs: ;
+    dcterms:provenance "Self"@en ;
+    skos:definition "The light-driven reduction (conversion) of carbon dioxide (CO2) to hydrocarbons and / or platform chemicals in presence of water. The absorption of light and the adsorption of the reactants is performed by a photocatalyst (usually a metal oxide). "@en ;
+    skos:member cs:0001013,
+        cs:0001047,
+        cs:0001099,
+        cs:0001133 ;
+    skos:prefLabel "Photocatalytic CO2 reduction"@en .
+
+cs:0001158 a skos:Collection ;
+    dcterms:identifier "photo_0001158"^^xsd:token ;
+    dcterms:isPartOf cs: ;
+    dcterms:provenance "Self"@en ;
+    skos:definition "Details describing the construction, physical dimensions, and operation of the photoreactor used for the photocalytic CO2 reduction reactions."@en ;
+    skos:member cs:0001061,
+        cs:0001073,
+        cs:0001089,
+        cs:0001107,
+        cs:0001112,
+        cs:0001113,
+        cs:0001115 ;
+    skos:prefLabel "Reactor design"@en .
+
+cs:0001159 a skos:Collection ;
+    dcterms:identifier "photo_0001159"^^xsd:token ;
+    dcterms:isPartOf cs: ;
+    dcterms:provenance "Self"@en ;
+    skos:definition "The process by which one or more chemical reactions are performed with the aim of converting a reactant or starting material into a product or multiple products."@en ;
+    skos:member cs:0001017,
+        cs:0001075,
+        cs:0001134 ;
+    skos:prefLabel "Synthesis of photocatalysts"@en .
+
+cs:0001160 a skos:Collection ;
+    dcterms:identifier "photo_0001160"^^xsd:token ;
+    dcterms:isPartOf cs: ;
+    dcterms:provenance "Self"@en ;
+    skos:definition "A collection of techniques used to identify the (physico)chemical, morphological, structural, mechanical, optical and electrical properties of the syntesized photocatalysts. Characterization is performed after the synthesis of the photocatalysts to evaluate the success of the synthetic approach, but also after the completion of the evaluation of the materials in CO2 photoreduction to ensure their stability under the selected experimental parameters."@en ;
+    skos:member cs:0001003,
+        cs:0001029,
+        cs:0001039,
+        cs:0001058,
+        cs:0001059,
+        cs:0001074,
+        cs:0001081,
+        cs:0001088,
+        cs:0001098,
+        cs:0001111,
+        cs:0001122,
+        cs:0001138,
+        cs:0001143,
+        cs:0001145,
+        cs:0001153,
+        cs:0001154,
+        cs:0001155 ;
+    skos:prefLabel "Characterization of photocatalysts"@en .
+
+cs:0001161 a skos:Collection ;
+    dcterms:identifier "photo_0001161"^^xsd:token ;
+    dcterms:isPartOf cs: ;
+    dcterms:provenance "Self"@en ;
+    skos:definition "Selection of experimental parameters applied for the evaluation of the performance of a photocatalyst in CO2 photoreduction."@en ;
+    skos:member cs:0001020,
+        cs:0001057,
+        cs:0001071,
+        cs:0001073,
+        cs:0001089,
+        cs:0001109,
+        cs:0001121,
+        cs:0001142 ;
+    skos:prefLabel "Evaluation of performance"@en .
+
+cs:0001001 a skos:Concept ;
+    dcterms:identifier "photo_0001001"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/general-terms> ;
+    skos:broader cs:0001062 ;
     skos:definition "The process of one material (absorbate) being retained by another (absorbent); this may be the physical solution of a gas, liquid, or solid in a liquid, attachement of molecules of a gas, vapour, liquid, or dissolved substance to a solid surface by physical forces; etc. In spectrometry, absorption of light at characteristic wavelengths or bands of wavelengths is used to identify the chemical nature of molecules, atoms or ions and to measure the concentration of these species. "@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Absorption"@en .
 
-<http://example.org/nfdi4cat/photo/atomic-force-microscopy> a skos:Concept ;
-    dcterms:identifier "atomic-force-microscopy"^^xsd:token ;
+cs:0001003 a skos:Concept ;
+    dcterms:identifier "photo_0001003"^^xsd:token ;
     dcterms:provenance "www.wikipedia.org"@en ;
     skos:altLabel "AFM"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/characterization-of-photocatalysts> ;
+    skos:broader cs:0001013 ;
     skos:definition "Atomic force microscopy (AFM) is a type of scanning probe microscopy (SPM), with demonstrated resolution on the order of fractions of a nanometer, more than 1000 times better than the optical diffraction limit. The information is gathered by \"feeling\" or \"touching\" the surface with a mechanical probe. Piezoelectric elements that facilitate tiny but accurate and precise movements on (electronic) command enable precise scanning."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Atomic force microscopy"@en .
 
-<http://example.org/nfdi4cat/photo/bandgap-energy> a skos:Concept ;
-    dcterms:identifier "bandgap-energy"^^xsd:token ;
+cs:0001004 a skos:Concept ;
+    dcterms:identifier "photo_0001004"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
-    skos:altLabel "Energy bandgap; Eg"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/general-terms> ;
+    skos:altLabel "Eg"@en,
+        "Energy bandgap"@en ;
+    skos:broader cs:0001062 ;
     skos:definition "The energy difference between the bottom of the conduction band and the top of the valence band in a semiconductor or an insulator."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Bandgap energy"@en .
 
-<http://example.org/nfdi4cat/photo/charge-photogeneration> a skos:Concept ;
-    dcterms:identifier "charge-photogeneration"^^xsd:token ;
+cs:0001014 a skos:Concept ;
+    dcterms:identifier "photo_0001014"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:altLabel "Photogenerated charges; Charge photo-generation; Electron excitation; Electron-hole pair;"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/general-terms> ;
+    skos:altLabel ""@en,
+        "Charge photo-generation"@en,
+        "Electron excitation"@en,
+        "Electron-hole pair"@en,
+        "Photogenerated charges"@en ;
+    skos:broader cs:0001062 ;
     skos:definition "The generation of electron - hole pairs in a semiconductor as a result of light absorption of sufficient energy to overcome the bandgap energy. Electrons (negative charge) get excited to the conduction band, while holes (positive charge) remain in the valence band. "@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Charge photogeneration"@en .
 
-<http://example.org/nfdi4cat/photo/charge-recombination> a skos:Concept ;
-    dcterms:identifier "charge-recombination"^^xsd:token ;
+cs:0001015 a skos:Concept ;
+    dcterms:identifier "photo_0001015"^^xsd:token ;
     dcterms:provenance "IUPAC / Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/general-terms> ;
+    skos:broader cs:0001062 ;
     skos:definition "The reverse of charge separation. The recombination of electrons and holes without them having enough time to reduce and oxidize (respectively) the adsorbed reactants, leads to lower efficiencies in CO2 photoreduction."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Charge recombination"@en .
 
-<http://example.org/nfdi4cat/photo/charge-separation> a skos:Concept ;
-    dcterms:identifier "charge-separation"^^xsd:token ;
+cs:0001016 a skos:Concept ;
+    dcterms:identifier "photo_0001016"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/general-terms> ;
+    skos:broader cs:0001062 ;
     skos:definition "A process in which, under the influence of a suitable driving force (e.g., provided by photoexcitation), electronic charge moves in a direction that increases the difference in local charges between donor and acceptor sites."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Charge separation"@en .
 
-<http://example.org/nfdi4cat/photo/concentration-of-reactants> a skos:Concept ;
-    dcterms:identifier "concentration-of-reactants"^^xsd:token ;
+cs:0001020 a skos:Concept ;
+    dcterms:identifier "photo_0001020"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/reactants> ;
+    skos:broader cs:0001114 ;
     skos:definition "Concentration of the reactants (e.g., CO2 and H2O) used in the photocatalytic CO2 reduction experiments"@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Concentration of reactants"@en .
 
-<http://example.org/nfdi4cat/photo/conduction-band> a skos:Concept ;
-    dcterms:identifier "conduction-band"^^xsd:token ;
+cs:0001021 a skos:Concept ;
+    dcterms:identifier "photo_0001021"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
     skos:altLabel "CB"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/general-terms> ;
+    skos:broader cs:0001062 ;
     skos:definition "A vacant or only partially occupied set of many closely spaced electronic levels resulting from an array of a large number of atoms forming a system in which the electrons can move freely or nearly so. This term is usually used to describe the properties of metals and semiconductors."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Conduction band"@en .
 
-<http://example.org/nfdi4cat/photo/crystallinity> a skos:Concept ;
-    dcterms:identifier "crystallinity"^^xsd:token ;
+cs:0001022 a skos:Concept ;
+    dcterms:identifier "photo_0001022"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/general-terms> ;
+    skos:broader cs:0001062 ;
     skos:definition "The presence of three-dimensional order in the level of atomic dimensions."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Crystallinity"@en .
 
-<http://example.org/nfdi4cat/photo/differential-scanning-calorimetry> a skos:Concept ;
-    dcterms:identifier "differential-scanning-calorimetry"^^xsd:token ;
+cs:0001029 a skos:Concept ;
+    dcterms:identifier "photo_0001029"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
     skos:altLabel "DSC"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/characterization-of-photocatalysts> ;
+    skos:broader cs:0001013 ;
     skos:definition "A technique in which the difference in energy inputs into a substance (and/or its reaction product(s)) and a reference material is measured as a function of temperature whilst the substance and reference material are subjected to a controlled temperature programme."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Differential scanning calorimetry"@en .
 
-<http://example.org/nfdi4cat/photo/doping> a skos:Concept ;
-    dcterms:identifier "doping"^^xsd:token ;
+cs:0001036 a skos:Concept ;
+    dcterms:identifier "photo_0001036"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/general-terms> ;
+    skos:broader cs:0001062 ;
     skos:definition "The action of adding a small amount of foreign atoms to form a solid solution in the lattice of a non-metallic catalyst."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Doping"@en .
 
-<http://example.org/nfdi4cat/photo/electron-energy-loss-spectroscopy> a skos:Concept ;
-    dcterms:identifier "electron-energy-loss-spectroscopy"^^xsd:token ;
+cs:0001039 a skos:Concept ;
+    dcterms:identifier "photo_0001039"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
     skos:altLabel "EELS"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/characterization-of-photocatalysts> ;
+    skos:broader cs:0001013 ;
     skos:definition "Any technique in which an electron transparent specimen is bombarded with a finely focused electron beam and the energy distribution of the transmitted electrons is measured. This energy spectrum contains features corresponding to discrete losses of energy of the transmitted electrons due to excitation of electronic or plasmon states and provides information on the identity (and in some cases) chemical bonding of the elements in the sample."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Electron energy loss spectroscopy"@en .
 
-<http://example.org/nfdi4cat/photo/electron-transfer> a skos:Concept ;
-    dcterms:identifier "electron-transfer"^^xsd:token ;
+cs:0001040 a skos:Concept ;
+    dcterms:identifier "photo_0001040"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/general-terms> ;
+    skos:broader cs:0001062 ;
     skos:definition "The transfer of an electron from one molecular entity to another, or between two localized sites in the same molecular entity."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Electron transfer"@en .
 
-<http://example.org/nfdi4cat/photo/equipment-controlling-and-monitoring-gas-flow> a skos:Concept ;
-    dcterms:identifier "equipment-controlling-and-monitoring-gas-flow"^^xsd:token ;
+cs:0001041 a skos:Concept ;
+    dcterms:identifier "photo_0001041"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/gas-flow> ;
+    skos:broader cs:0001061 ;
     skos:definition "Equipment used for controlling and / or monitoring the flow of gases (reactant or inert) needed for a CO2 photoreduction experiment. Mass flow controllers (MFCs) are commonly used to controlle gas flows."@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/mass-flow-controller> ;
+    skos:narrower cs:0001077 ;
     skos:prefLabel "Equipment controlling and monitoring gas flow"@en .
 
-<http://example.org/nfdi4cat/photo/equipment-for-controlling-and-monitoring-operation-pressure> a skos:Concept ;
-    dcterms:identifier "equipment-for-controlling-and-monitoring-operation-pressure"^^xsd:token ;
+cs:0001042 a skos:Concept ;
+    dcterms:identifier "photo_0001042"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:altLabel "Pressure controller; Pressure gauge; Pressure monitor"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/range-of-operation-pressure> ;
+    skos:altLabel "Pressure controller"@en,
+        "Pressure gauge"@en,
+        "Pressure monitor"@en ;
+    skos:broader cs:0001112 ;
     skos:definition "Equipment used for controlling and / or monitoring the pressure in various parts of a photoreactor. A vaccum pump is a typical example of such equipment."@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/vacuum-pump> ;
+    skos:narrower cs:0001146 ;
     skos:prefLabel "Equipment for controlling and monitoring operation pressure"@en .
 
-<http://example.org/nfdi4cat/photo/excited-state> a skos:Concept ;
-    dcterms:identifier "excited-state"^^xsd:token ;
+cs:0001049 a skos:Concept ;
+    dcterms:identifier "photo_0001049"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/general-terms> ;
+    skos:broader cs:0001062 ;
     skos:definition "State of a system with energy higher than that if the ground state. This term is most commonly used to characterize a molecule  in one of its electonically excited states, but can also refer to vibrational and/or rotational excitation in the electronic ground state."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Excited state"@en .
 
-<http://example.org/nfdi4cat/photo/fermi-level> a skos:Concept ;
-    dcterms:identifier "fermi-level"^^xsd:token ;
+cs:0001050 a skos:Concept ;
+    dcterms:identifier "photo_0001050"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
     skos:altLabel "EF"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/general-terms> ;
+    skos:broader cs:0001062 ;
     skos:definition "The chemical potential of electrons in a solid (metals, semiconductors or insulators) or in an electrolyte solution."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Fermi level"@en .
 
-<http://example.org/nfdi4cat/photo/fourier-transform-infrared-spectroscopy> a skos:Concept ;
-    dcterms:identifier "fourier-transform-infrared-spectroscopy"^^xsd:token ;
+cs:0001058 a skos:Concept ;
+    dcterms:identifier "photo_0001058"^^xsd:token ;
     dcterms:provenance "www.wikipedia.org"@en ;
     skos:altLabel "FT-IR"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/characterization-of-photocatalysts> ;
+    skos:broader cs:0001013 ;
     skos:definition "Measurement technique whereby spectra are collected based on measurements of the temporal coherence of an (infrared radiative source, using time-domain measurements of the electromagnetic radiation or other type of radiation."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Fourier transform infrared spectroscopy"@en .
 
-<http://example.org/nfdi4cat/photo/gaseous-environment> a skos:Concept ;
-    dcterms:identifier "gaseous-environment"^^xsd:token ;
+cs:0001060 a skos:Concept ;
+    dcterms:identifier "photo_0001060"^^xsd:token ;
     dcterms:provenance "Self"@en ;
     skos:altLabel "Calcination environment"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/calcination-steps> ;
+    skos:broader cs:0001009 ;
     skos:definition "A gas flow under which the calcination step takes place (e,g,, Ar or synthetic air)"@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/flow-rate-of-gas-used-for-calcination> ;
+    skos:narrower cs:0001054 ;
     skos:prefLabel "Gaseous environment"@en .
 
-<http://example.org/nfdi4cat/photo/ground-state> a skos:Concept ;
-    dcterms:identifier "ground-state"^^xsd:token ;
+cs:0001064 a skos:Concept ;
+    dcterms:identifier "photo_0001064"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/general-terms> ;
+    skos:broader cs:0001062 ;
     skos:definition "The state of lowest Gibbs energy of a system"@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Ground state"@en .
 
-<http://example.org/nfdi4cat/photo/hole-transfer> a skos:Concept ;
-    dcterms:identifier "hole-transfer"^^xsd:token ;
+cs:0001066 a skos:Concept ;
+    dcterms:identifier "photo_0001066"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/general-terms> ;
+    skos:broader cs:0001062 ;
     skos:definition "Charge migration process in which the majority carriers are positively charged."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Hole transfer"@en .
 
-<http://example.org/nfdi4cat/photo/irradiation-time> a skos:Concept ;
-    dcterms:identifier "irradiation-time"^^xsd:token ;
+cs:0001071 a skos:Concept ;
+    dcterms:identifier "photo_0001071"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/total-duration-of-experiment> ;
+    skos:broader cs:0001142 ;
     skos:definition "The total duration in which the photocatalyst was under irradiation by the selected light source. "@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Irradiation time"@en .
 
-<http://example.org/nfdi4cat/photo/liquid-chromatography> a skos:Concept ;
-    dcterms:identifier "liquid-chromatography"^^xsd:token ;
+cs:0001074 a skos:Concept ;
+    dcterms:identifier "photo_0001074"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
     skos:altLabel "LC"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/characterization-of-photocatalysts> ;
+    skos:broader cs:0001013 ;
     skos:definition "A separation technique in which the mobile phase is a liquid. Liquid chromatography can be carried out either in a column or on a plane. Present-day liquid chromatography generally utilizing very small particles and a relatively high inlet pressure is often characterized by the term high-performance (or high-pressure) liquid chromatography, and the acronym HPLC."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Liquid chromatography"@en .
 
-<http://example.org/nfdi4cat/photo/mass-spectroscopy> a skos:Concept ;
-    dcterms:identifier "mass-spectroscopy"^^xsd:token ;
+cs:0001081 a skos:Concept ;
+    dcterms:identifier "photo_0001081"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
     skos:altLabel "MS"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/characterization-of-photocatalysts> ;
+    skos:broader cs:0001013 ;
     skos:definition "The study of systems by causing the formation of gaseous ions, with or without fragmentation, which are then characterized by their mass-to-charge ratios and relative abundances."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Mass spectroscopy"@en .
 
-<http://example.org/nfdi4cat/photo/metal-oxide> a skos:Concept ;
-    dcterms:identifier "metal-oxide"^^xsd:token ;
+cs:0001086 a skos:Concept ;
+    dcterms:identifier "photo_0001086"^^xsd:token ;
     dcterms:provenance "Encyclopedia Britannica"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/general-terms> ;
+    skos:broader cs:0001062 ;
     skos:definition "Metal oxides are crystalline solids that contain a metal cation and an oxide anion."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Metal oxide"@en .
 
-<http://example.org/nfdi4cat/photo/nuclear-magnetic-resonance-spectroscopy> a skos:Concept ;
-    dcterms:identifier "nuclear-magnetic-resonance-spectroscopy"^^xsd:token ;
+cs:0001088 a skos:Concept ;
+    dcterms:identifier "photo_0001088"^^xsd:token ;
     dcterms:provenance "www.wikipedia.org"@en ;
     skos:altLabel "NMR"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/characterization-of-photocatalysts> ;
+    skos:broader cs:0001013 ;
     skos:definition "Nuclear magnetic resonance spectroscopy, most commonly known as NMR spectroscopy or magnetic resonance spectroscopy (MRS), is a spectroscopic technique to observe local magnetic fields around atomic nuclei. "@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Nuclear magnetic resonance spectroscopy"@en .
 
-<http://example.org/nfdi4cat/photo/oxidation> a skos:Concept ;
-    dcterms:identifier "oxidation"^^xsd:token ;
+cs:0001092 a skos:Concept ;
+    dcterms:identifier "photo_0001092"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/general-terms> ;
+    skos:broader cs:0001062 ;
     skos:definition "1. The complete, net removal of one or more electrons from a molecular entity. 2. An increase in the oxidation number of any atom within any substrate. 3. Gain of oxygen and / or loss of hydrogen of an organic substrate,"@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Oxidation "@en .
 
-<http://example.org/nfdi4cat/photo/photocatalyst> a skos:Concept ;
-    dcterms:identifier "photocatalyst"^^xsd:token ;
+cs:0001094 a skos:Concept ;
+    dcterms:identifier "photo_0001094"^^xsd:token ;
     dcterms:provenance "IUPAC Gold Book"@en ;
     skos:altLabel "Photocatalytic material"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/general-terms> ;
+    skos:broader cs:0001062 ;
     skos:definition "Catalyst able to produce, upon absorption of light, chemical transformations of the reaction partners. The excited state of the photocatalyst repeatedly interacts with the reaction partners forming reaction intermediates and regenerates itself after each cycle of such interactions."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Photocatalyst"@en .
 
-<http://example.org/nfdi4cat/photo/photoexcitation> a skos:Concept ;
-    dcterms:identifier "photoexcitation"^^xsd:token ;
+cs:0001097 a skos:Concept ;
+    dcterms:identifier "photo_0001097"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
     skos:altLabel "Photo-excitation"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/general-terms> ;
+    skos:broader cs:0001062 ;
     skos:definition "The production of an excited state by the adsorption of ultraviolet, visible, or infrared radiation. "@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Photoexcitation"@en .
 
-<http://example.org/nfdi4cat/photo/photoluminescence> a skos:Concept ;
-    dcterms:identifier "photoluminescence"^^xsd:token ;
+cs:0001098 a skos:Concept ;
+    dcterms:identifier "photo_0001098"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
     skos:altLabel "PL"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/characterization-of-photocatalysts> ;
+    skos:broader cs:0001013 ;
     skos:definition "Luminescence from direct photoexcitation of the emitting species."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Photoluminescence"@en .
 
-<http://example.org/nfdi4cat/photo/pore-size-distribution> a skos:Concept ;
-    dcterms:identifier "pore-size-distribution"^^xsd:token ;
+cs:0001100 a skos:Concept ;
+    dcterms:identifier "photo_0001100"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/general-terms> ;
+    skos:broader cs:0001062 ;
     skos:definition "The distribution of pore volume with respect to pore size; alternatively, it may be defined by the related distribution of pore area with respect to pore size."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Pore size distribution"@en .
 
-<http://example.org/nfdi4cat/photo/powdered-photocatalyst> a skos:Concept ;
-    dcterms:identifier "powdered-photocatalyst"^^xsd:token ;
+cs:0001101 a skos:Concept ;
+    dcterms:identifier "photo_0001101"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/form-of-photocatalyst> ;
+    skos:broader cs:0001057 ;
     skos:definition "A photocatalyst introduced to the reaction chamber in the form of a powder. Usually the powdered photocatalyst is spread inside a quartz / glass plate."@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/mass-of-powder-used> ;
+    skos:narrower cs:0001079 ;
     skos:prefLabel "Powdered photocatalyst"@en .
 
-<http://example.org/nfdi4cat/photo/pressure-drop-in-a-co2-phoreduction-experiment> a skos:Concept ;
-    dcterms:identifier "pressure-drop-in-a-co2-phoreduction-experiment"^^xsd:token ;
+cs:0001104 a skos:Concept ;
+    dcterms:identifier "photo_0001104"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/photocatalytic-co2-reduction-experiment> ;
+    skos:broader cs:0001096 ;
     skos:definition "When performing a CO2 photoreduction experiment in batch mode, with each sampling event, the pressure in the reaction chamber decreases. This pressure drop should be taken into consideration when calculating the concentration of formed products."@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/pressure-drop> ;
+    skos:narrower cs:0001103 ;
     skos:prefLabel "Pressure drop in a CO2 phoreduction experiment"@en .
 
-<http://example.org/nfdi4cat/photo/purity-of-reactants> a skos:Concept ;
-    dcterms:identifier "purity-of-reactants"^^xsd:token ;
+cs:0001109 a skos:Concept ;
+    dcterms:identifier "photo_0001109"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/reactants> ;
+    skos:broader cs:0001114 ;
     skos:definition "Purity of reactants (e.g., CO2, H2O, He) used in the photocatalytic CO2 reduction experiments. Purity is measure of the impurities contained in the reactants' supply. The highest purity reactants should be used to ensure the collection of reliable results. "@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Purity of reactants"@en .
 
-<http://example.org/nfdi4cat/photo/raman-spectroscopy> a skos:Concept ;
-    dcterms:identifier "raman-spectroscopy"^^xsd:token ;
+cs:0001111 a skos:Concept ;
+    dcterms:identifier "photo_0001111"^^xsd:token ;
     dcterms:provenance "www.wikipedia.org"@en ;
     skos:altLabel "RAMAN"@en,
         "Raman"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/characterization-of-photocatalysts> ;
+    skos:broader cs:0001013 ;
     skos:definition "Raman spectroscopy is a spectroscopic technique typically used to determine vibrational modes of molecules, although rotational and other low-frequency modes of systems may also be observed."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Raman Spectroscopy"@en .
 
-<http://example.org/nfdi4cat/photo/reduction> a skos:Concept ;
-    dcterms:identifier "reduction"^^xsd:token ;
+cs:0001116 a skos:Concept ;
+    dcterms:identifier "photo_0001116"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/general-terms> ;
+    skos:broader cs:0001062 ;
     skos:definition "The complete transfer of one or more electrons to a molecular entity."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Reduction"@en .
 
-<http://example.org/nfdi4cat/photo/sampling-intervals> a skos:Concept ;
-    dcterms:identifier "sampling-intervals"^^xsd:token ;
+cs:0001121 a skos:Concept ;
+    dcterms:identifier "photo_0001121"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/total-duration-of-experiment> ;
+    skos:broader cs:0001142 ;
     skos:definition "The time in between the collection of two data points."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Sampling intervals"@en .
 
-<http://example.org/nfdi4cat/photo/scanning-electron-microscopy> a skos:Concept ;
-    dcterms:identifier "scanning-electron-microscopy"^^xsd:token ;
+cs:0001122 a skos:Concept ;
+    dcterms:identifier "photo_0001122"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
     skos:altLabel "SEM"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/characterization-of-photocatalysts> ;
+    skos:broader cs:0001013 ;
     skos:definition "Any analytical technique which involves the generation and evaluation of secondary electrons (and to a lesser extent back scattered electrons) by a finely focused electron beam (typically 10 nm or less) for high resolution and high depth of field imaging."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Scanning electron microscopy"@en .
 
-<http://example.org/nfdi4cat/photo/semiconductor> a skos:Concept ;
-    dcterms:identifier "semiconductor"^^xsd:token ;
+cs:0001125 a skos:Concept ;
+    dcterms:identifier "photo_0001125"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/general-terms> ;
+    skos:broader cs:0001062 ;
     skos:definition "Material whose conductivity, due to charges of both signs, is normally in the range between that of metals and insulators and in which the electric charge carrier density can be changed by external means."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Semiconductor"@en .
 
-<http://example.org/nfdi4cat/photo/specific-surface-area> a skos:Concept ;
-    dcterms:identifier "specific-surface-area"^^xsd:token ;
+cs:0001129 a skos:Concept ;
+    dcterms:identifier "photo_0001129"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
     skos:altLabel "SSA"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/general-terms> ;
+    skos:broader cs:0001062 ;
     skos:definition "When the area of the interface between two phases is proportional to the mass of one of the phases (e.g., for a solid adsorbent, for an emulsion or for an aerosol), the specific surface area is defined as the surface area divided by the mass of the relevant phase. "@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Specific surface area"@en .
 
-<http://example.org/nfdi4cat/photo/thermogravimetric-analysis> a skos:Concept ;
-    dcterms:identifier "thermogravimetric-analysis"^^xsd:token ;
+cs:0001138 a skos:Concept ;
+    dcterms:identifier "photo_0001138"^^xsd:token ;
     dcterms:provenance "www.wikipedia.org"@en ;
     skos:altLabel "TGA"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/characterization-of-photocatalysts> ;
+    skos:broader cs:0001013 ;
     skos:definition "Thermogravimetric analysis or thermal gravimetric analysis (TGA) is a method of thermal analysis in which the mass of a sample is measured over time as the temperature changes. This measurement provides information about physical phenomena, such as phase transitions, absorption, adsorption and desorption; as well as chemical phenomena including chemisorptions, thermal decomposition, and solid-gas reactions (e.g., oxidation or reduction)"@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Thermogravimetric analysis"@en .
 
-<http://example.org/nfdi4cat/photo/transmission-electron-microscopy> a skos:Concept ;
-    dcterms:identifier "transmission-electron-microscopy"^^xsd:token ;
+cs:0001143 a skos:Concept ;
+    dcterms:identifier "photo_0001143"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
     skos:altLabel "TEM"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/characterization-of-photocatalysts> ;
+    skos:broader cs:0001013 ;
     skos:definition "Any technique in which an electron transparent sample is bombarded with an electron beam and the intensity of the transmitted electrons which is determined by scattering phenomena (electron absorption phenomena) in the interior of the sample is recorded. TEM essentially provides a high resolution image of the microstructure of a thin sample. This technique is often just called electron microscopy. The term transmission electron microscopy is however recommended for the sake of a clear distinction from other electron microscopic techniques."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Transmission electron microscopy"@en .
 
-<http://example.org/nfdi4cat/photo/ultraviolet-visible-spectroscopy> a skos:Concept ;
-    dcterms:identifier "ultraviolet-visible-spectroscopy"^^xsd:token ;
+cs:0001145 a skos:Concept ;
+    dcterms:identifier "photo_0001145"^^xsd:token ;
     dcterms:provenance "www.wikipedia.org"@en ;
     skos:altLabel "UV-Vis"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/characterization-of-photocatalysts> ;
+    skos:broader cs:0001013 ;
     skos:definition "Refers to absorption spectroscopy or reflectance spectroscopy in part of the ultraviolet and the full, adjacent visible regions of the electromagnetic spectrum. This means it uses light in the visible and adjacent ranges. The absorption or reflectance in the visible range directly affects the perceived color of the chemicals involved. In this region of the spectrum, atoms and molecules undergo electronic transitions."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Ultraviolet-visible spectroscopy"@en .
 
-<http://example.org/nfdi4cat/photo/valence-band> a skos:Concept ;
-    dcterms:identifier "valence-band"^^xsd:token ;
+cs:0001147 a skos:Concept ;
+    dcterms:identifier "photo_0001147"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
     skos:altLabel "VB"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/general-terms> ;
+    skos:broader cs:0001062 ;
     skos:definition "Highest energy continuum of energy levels in a solid that is fully occupied by electrons at 0 K. The valence band is lower in energy than the conduction band and is generally completely full in semiconductors."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Valence band"@en .
 
-<http://example.org/nfdi4cat/photo/wavelength> a skos:Concept ;
-    dcterms:identifier "wavelength"^^xsd:token ;
+cs:0001151 a skos:Concept ;
+    dcterms:identifier "photo_0001151"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
     skos:altLabel "λ"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/general-terms> ;
+    skos:broader cs:0001062 ;
     skos:definition "Distance in the direction of propagation of a periodic wave between two successive points where at a given the phase is the same."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Wavelength"@en .
 
-<http://example.org/nfdi4cat/photo/x-ray-diffraction> a skos:Concept ;
-    dcterms:identifier "x-ray-diffraction"^^xsd:token ;
+cs:0001153 a skos:Concept ;
+    dcterms:identifier "photo_0001153"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
     skos:altLabel "XRD"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/characterization-of-photocatalysts> ;
+    skos:broader cs:0001013 ;
     skos:definition "Any technique which utilizes the diffraction of X-rays generated in a microstructural domain of a solid under bombardment with a finely focused electron beam, thus providing an X-ray diffraction pattern of this microstructural domain."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "X-ray diffraction"@en .
 
-<http://example.org/nfdi4cat/photo/x-ray-fluorescence> a skos:Concept ;
-    dcterms:identifier "x-ray-fluorescence"^^xsd:token ;
+cs:0001154 a skos:Concept ;
+    dcterms:identifier "photo_0001154"^^xsd:token ;
     dcterms:provenance "Dictionary of Applied Math for Engineers and Scientists, "@en ;
     skos:altLabel "XRF"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/characterization-of-photocatalysts> ;
+    skos:broader cs:0001013 ;
     skos:definition "A kind of analysis based on the measurement of the energies and intensities of characteristic X-radiation emitted by a test portion during irradiation with electromagnetic radiation."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "X-ray fluorescence"@en .
 
-<http://example.org/nfdi4cat/photo/x-ray-photoelectron-spectroscopy> a skos:Concept ;
-    dcterms:identifier "x-ray-photoelectron-spectroscopy"^^xsd:token ;
+cs:0001155 a skos:Concept ;
+    dcterms:identifier "photo_0001155"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
     skos:altLabel "XPS"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/characterization-of-photocatalysts> ;
+    skos:broader cs:0001013 ;
     skos:definition "Any technique in which the sample is bombarded with X-rays and photoelectrons produced by the sample are detected as a function of energy. ESCA (Electron Spectroscopy for Chemical Analysis) refers to the use of this technique to identify elements, their concentrations, and their chemical state within the sample."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "X-ray photoelectron spectroscopy"@en .
 
-<http://example.org/nfdi4cat/photo/chemical-substances-used-for-synthesis> a skos:Concept ;
-    dcterms:identifier "chemical-substances-used-for-synthesis"^^xsd:token ;
+cs:0001017 a skos:Concept ;
+    dcterms:identifier "photo_0001017"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:altLabel "Chemicals; Chemical reagents; Reagents"@en ;
+    skos:altLabel "Chemical reagents"@en,
+        "Chemicals"@en,
+        "Reagents"@en ;
     skos:definition "Chemical substances used in the synthesis process of a desired photocatalyst."@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/masses-volumes-concentrations-of-chemicals-used-in-synthesis> ;
+    skos:narrower cs:0001076 ;
     skos:prefLabel "Chemical substances used for synthesis"@en ;
     skos:topConceptOf cs: .
 
-<http://example.org/nfdi4cat/photo/deposited-film> a skos:Concept ;
-    dcterms:identifier "deposited-film"^^xsd:token ;
+cs:0001025 a skos:Concept ;
+    dcterms:identifier "photo_0001025"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/thin-film> ;
+    skos:broader cs:0001141 ;
     skos:definition "A thin film of the photocatalyst deposited on an appropiate for the application substrate."@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/dimensions-of-deposited-film>,
-        <http://example.org/nfdi4cat/photo/mass-of-deposited-film> ;
+    skos:narrower cs:0001030,
+        cs:0001078 ;
     skos:prefLabel "Deposited film"@en .
 
-<http://example.org/nfdi4cat/photo/dimensions-of-deposited-film> a skos:Concept ;
-    dcterms:identifier "dimensions-of-deposited-film"^^xsd:token ;
+cs:0001030 a skos:Concept ;
+    dcterms:identifier "photo_0001030"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/deposited-film> ;
+    skos:broader cs:0001025 ;
     skos:definition "The diamensions (area / thickness / diameter) of the - deposited on the substrate - thin film"@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/area-of-deposited-film>,
-        <http://example.org/nfdi4cat/photo/thickness-of-deposited-film> ;
+    skos:narrower cs:0001002,
+        cs:0001139 ;
     skos:prefLabel "Dimensions of deposited film"@en .
 
-<http://example.org/nfdi4cat/photo/dimensions-of-optical-window> a skos:Concept ;
-    dcterms:identifier "dimensions-of-optical-window"^^xsd:token ;
+cs:0001031 a skos:Concept ;
+    dcterms:identifier "photo_0001031"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/optical-window> ;
+    skos:broader cs:0001090 ;
     skos:definition "The dimension of the optical window (diameter / thickness) allowing the incoming light to enter the reaction chamber and interact with the photocatalyst."@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/diameter-of-optical-window>,
-        <http://example.org/nfdi4cat/photo/thickness-of-optical-window> ;
+    skos:narrower cs:0001027,
+        cs:0001140 ;
     skos:prefLabel "Dimensions of optical window"@en .
 
-<http://example.org/nfdi4cat/photo/gas-flow> a skos:Concept ;
-    dcterms:identifier "gas-flow"^^xsd:token ;
+cs:0001061 a skos:Concept ;
+    dcterms:identifier "photo_0001061"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/photoreactor-design> ;
+    skos:broader cs:0001099 ;
     skos:definition "Flow rates of gases used in a CO2 photoreduction experiment. Gases can have either the role of a reactant (e.g., CO2) or be inert (e.g., Ar, He). "@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/equipment-controlling-and-monitoring-gas-flow> ;
+    skos:narrower cs:0001041 ;
     skos:prefLabel "Gas flow"@en .
 
-<http://example.org/nfdi4cat/photo/infrared> a skos:Concept ;
-    dcterms:identifier "infrared"^^xsd:token ;
+cs:0001068 a skos:Concept ;
+    dcterms:identifier "photo_0001068"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
-    skos:altLabel "IR; Ir"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/general-terms>,
-        <http://example.org/nfdi4cat/photo/wavelength-range> ;
+    skos:altLabel "IR"@en,
+        "Ir"@en ;
+    skos:broader cs:0001062,
+        cs:0001152 ;
     skos:definition "Region of the electromagnetic spectrum extending from 780 nm to about 20000 nm. This is the wavelength region in which absorption by a molecular entity causes excitation of its vibrational, rotational, and bending modes."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Infrared"@en .
 
-<http://example.org/nfdi4cat/photo/optical-window> a skos:Concept ;
-    dcterms:identifier "optical-window"^^xsd:token ;
+cs:0001090 a skos:Concept ;
+    dcterms:identifier "photo_0001090"^^xsd:token ;
     dcterms:provenance "www.edmundoptics.com"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/reaction-chamber> ;
+    skos:broader cs:0001115 ;
     skos:definition " Flat, optically transparent plates that are typically designed to maximize transmission in a specified wavelength range, while minimizing reflection and absoprtion."@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/dimensions-of-optical-window>,
-        <http://example.org/nfdi4cat/photo/material-of-optical-window> ;
+    skos:narrower cs:0001031,
+        cs:0001082 ;
     skos:prefLabel "Optical window"@en .
 
-<http://example.org/nfdi4cat/photo/range-of-operation-pressure> a skos:Concept ;
-    dcterms:identifier "range-of-operation-pressure"^^xsd:token ;
+cs:0001112 a skos:Concept ;
+    dcterms:identifier "photo_0001112"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:altLabel "Operation pressure; Operation pressure range; Pressure range"@en ;
+    skos:altLabel "Operation pressure"@en,
+        "Operation pressure range"@en,
+        "Pressure range"@en ;
     skos:definition "Maximum and minimum of operation pressure range within the reactor can operate safely. Higher operation temperatures can lead to higher pressure values."@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/equipment-for-controlling-and-monitoring-operation-pressure> ;
+    skos:narrower cs:0001042 ;
     skos:prefLabel "Range of operation pressure"@en ;
     skos:topConceptOf cs: .
 
-<http://example.org/nfdi4cat/photo/range-of-operation-temperature> a skos:Concept ;
-    dcterms:identifier "range-of-operation-temperature"^^xsd:token ;
+cs:0001113 a skos:Concept ;
+    dcterms:identifier "photo_0001113"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:altLabel "Operation temperature; Operation temperature range; Temparature range"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/photoreactor-design> ;
+    skos:altLabel "Operation temperature"@en,
+        "Operation temperature range"@en,
+        "Temparature range"@en ;
+    skos:broader cs:0001099 ;
     skos:definition "Maximum and minimum of operation temperature range within the reactor can operate safely."@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/equipment-for-controlling-and-monitoring-operation-temperature> ;
+    skos:narrower cs:0001043 ;
     skos:prefLabel "Range of operation temperature"@en .
 
-<http://example.org/nfdi4cat/photo/sacrificial-reagents> a skos:Concept ;
-    dcterms:identifier "sacrificial-reagents"^^xsd:token ;
+cs:0001119 a skos:Concept ;
+    dcterms:identifier "photo_0001119"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/reactants> ;
+    skos:broader cs:0001114 ;
     skos:definition "Electron donors or hole scavengers used to reduce the recombination tendency of electrons and holes. Sacrificial reagents are used in photocatalysis to study an oxidation or reduction reaction seperately."@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/sacrificial-acceptor>,
-        <http://example.org/nfdi4cat/photo/sacrificial-donor> ;
+    skos:narrower cs:0001117,
+        cs:0001118 ;
     skos:prefLabel "Sacrificial reagents"@en .
 
-<http://example.org/nfdi4cat/photo/selected-light-source> a skos:Concept ;
-    dcterms:identifier "selected-light-source"^^xsd:token ;
+cs:0001123 a skos:Concept ;
+    dcterms:identifier "photo_0001123"^^xsd:token ;
     dcterms:provenance "Self"@en ;
     skos:definition "The light source used for the irradiation of the reactants in the reaction chamber."@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/light-intensity>,
-        <http://example.org/nfdi4cat/photo/wavelength-range> ;
+    skos:narrower cs:0001072,
+        cs:0001152 ;
     skos:prefLabel "Selected light source"@en ;
     skos:topConceptOf cs: .
 
-<http://example.org/nfdi4cat/photo/substrate> a skos:Concept ;
-    dcterms:identifier "substrate"^^xsd:token ;
+cs:0001132 a skos:Concept ;
+    dcterms:identifier "photo_0001132"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/thin-film> ;
+    skos:broader cs:0001141 ;
     skos:definition "The substate onto which a (powdered) photocatalyst is deposited. Such substrates incude glass surfaces (e.g., borosilicate glass or conductive glass like ITO and FTO), ceramic substrates (e.g., alumina) or metal substrates (e.g., Ti foils, stainless steel etc.) "@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/dimensions-of-substrate>,
-        <http://example.org/nfdi4cat/photo/material-of-substrate> ;
+    skos:narrower cs:0001033,
+        cs:0001084 ;
     skos:prefLabel "Substrate"@en .
 
-<http://example.org/nfdi4cat/photo/ultraviolet> a skos:Concept ;
-    dcterms:identifier "ultraviolet"^^xsd:token ;
+cs:0001144 a skos:Concept ;
+    dcterms:identifier "photo_0001144"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
     skos:altLabel "UV"@en,
         "UV-A"@en,
         "UV-B"@en,
         "UV-C"@en,
         "VUV"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/general-terms>,
-        <http://example.org/nfdi4cat/photo/wavelength-range> ;
+    skos:broader cs:0001062,
+        cs:0001152 ;
     skos:definition "Region of the electromagnetic spectrum extending from about 100 nm to 400 nm. This region is divided into four sub-bands as follows: 1) Vacuum Ultraviolet (VUV): 100 - 200 nm, 2) UV-C: 200 - 280 nm, 3) UV-B: 280 - 315 nm, 4) UV-A: 315 - 400 nm"@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Ultraviolet"@en .
 
-<http://example.org/nfdi4cat/photo/visible> a skos:Concept ;
-    dcterms:identifier "visible"^^xsd:token ;
+cs:0001148 a skos:Concept ;
+    dcterms:identifier "photo_0001148"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
-    skos:altLabel "Vis; VIS"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/general-terms>,
-        <http://example.org/nfdi4cat/photo/wavelength-range> ;
+    skos:altLabel "VIS"@en,
+        "Vis"@en ;
+    skos:broader cs:0001062,
+        cs:0001152 ;
     skos:definition "Region of the electromagnetic spectrum extending from about 400 nm to 760 nm. This is the wavelength region to which the human eye is sensitive. There are no precise limits for the spectral range of visible radiation since they depend upon the amount or radiant power reaching the retina and on the responsivity of the observer."@en ;
     skos:inScheme cs: ;
     skos:prefLabel "Visible"@en .
 
-<http://example.org/nfdi4cat/photo/deposition-technique> a skos:Concept ;
-    dcterms:identifier "deposition-technique"^^xsd:token ;
+cs:0001026 a skos:Concept ;
+    dcterms:identifier "photo_0001026"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/thin-film> ;
+    skos:broader cs:0001141 ;
     skos:definition "A technique used to deposit (immobilize) a (powdered) photocatalyst on a substate. These techniques indlude (but are not limited to): doctor blading, spin coating, spray coating, etc."@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/doctor-blading>,
-        <http://example.org/nfdi4cat/photo/spin-coating>,
-        <http://example.org/nfdi4cat/photo/spray-coating> ;
+    skos:narrower cs:0001035,
+        cs:0001130,
+        cs:0001131 ;
     skos:prefLabel "Deposition technique"@en .
 
-<http://example.org/nfdi4cat/photo/equipped-detectors-of-gas-chromatograph> a skos:Concept ;
-    dcterms:identifier "equipped-detectors-of-gas-chromatograph"^^xsd:token ;
+cs:0001045 a skos:Concept ;
+    dcterms:identifier "photo_0001045"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/gas-chromatography> ;
+    skos:broader cs:0001059 ;
     skos:definition "Detectors of the gas chromatogragh used to identify the reaction products and intemediates."@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/dielectric-barrier-discharge-ionization-detector>,
-        <http://example.org/nfdi4cat/photo/flame-ionization-detector>,
-        <http://example.org/nfdi4cat/photo/thermal-conductivity-detector> ;
+    skos:narrower cs:0001028,
+        cs:0001052,
+        cs:0001137 ;
     skos:prefLabel "Equipped detectors of gas chromatograph"@en .
 
-<http://example.org/nfdi4cat/photo/form-of-photocatalyst> a skos:Concept ;
-    dcterms:identifier "form-of-photocatalyst"^^xsd:token ;
+cs:0001057 a skos:Concept ;
+    dcterms:identifier "photo_0001057"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/evaluation-of-performance> ;
+    skos:broader cs:0001047 ;
     skos:definition "The form in which the photocatalyst is introduced to the reaction chamber. This can include e.g., powders, pellets or thin films deposited on a substrate. "@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/powdered-photocatalyst>,
-        <http://example.org/nfdi4cat/photo/thin-film> ;
+    skos:narrower cs:0001101,
+        cs:0001141 ;
     skos:prefLabel "Form of photocatalyst"@en .
 
-<http://example.org/nfdi4cat/photo/literature-research> a skos:Concept ;
-    dcterms:identifier "literature-research"^^xsd:token ;
+cs:0001075 a skos:Concept ;
+    dcterms:identifier "photo_0001075"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:altLabel "Publications; papers; manuscripts;"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/synthesis-of-photocatalysts> ;
+    skos:altLabel ""@en,
+        "Publications"@en,
+        "manuscripts"@en,
+        "papers"@en ;
+    skos:broader cs:0001133 ;
     skos:definition "Thorough search of available literature on the research topic of interest using online research platforms (e.g, Scopus, Google Scholar, Web of Science, Research Gate etc.) and / or libraries. Relevant literature can be found in the form of publications, books, abstracts and conference presentations. "@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/collection-of-publications-of-interest>,
-        <http://example.org/nfdi4cat/photo/organization-of-literature-in-a-citation-management-software> ;
+    skos:narrower cs:0001019,
+        cs:0001091 ;
     skos:prefLabel "Literature research"@en .
 
-<http://example.org/nfdi4cat/photo/mass-spectrometry> a skos:Concept ;
-    dcterms:identifier "mass-spectrometry"^^xsd:token ;
+cs:0001080 a skos:Concept ;
+    dcterms:identifier "photo_0001080"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
     skos:altLabel "MS"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/product-identification-method> ;
+    skos:broader cs:0001107 ;
     skos:definition "The study of systems by causing the formation of gaseous ions, with or without fragmentation, which are then characterized by their mass-to-charge ratios and relative abundances."@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/calibration-of-mass-spectrometer>,
-        <http://example.org/nfdi4cat/photo/equipped-detectors-of-mass-spectrometer>,
-        <http://example.org/nfdi4cat/photo/sensitivity-of-mass-spectrometer> ;
+    skos:narrower cs:0001011,
+        cs:0001046,
+        cs:0001127 ;
     skos:prefLabel "Mass spectrometry"@en .
 
-<http://example.org/nfdi4cat/photo/material-of-substrate> a skos:Concept ;
-    dcterms:identifier "material-of-substrate"^^xsd:token ;
+cs:0001084 a skos:Concept ;
+    dcterms:identifier "photo_0001084"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/substrate> ;
+    skos:broader cs:0001132 ;
     skos:definition "The material that the substrate is made of. Common materials include: glass (conductive or not), ceramics and metal."@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/ceramic-substrate>,
-        <http://example.org/nfdi4cat/photo/glass-substrate>,
-        <http://example.org/nfdi4cat/photo/metallic-substrate> ;
+    skos:narrower cs:0001012,
+        cs:0001063,
+        cs:0001085 ;
     skos:prefLabel "Material of substrate"@en .
 
-<http://example.org/nfdi4cat/photo/product-identification-method> a skos:Concept ;
-    dcterms:identifier "product-identification-method"^^xsd:token ;
+cs:0001107 a skos:Concept ;
+    dcterms:identifier "photo_0001107"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/photoreactor-design> ;
+    skos:broader cs:0001099 ;
     skos:definition "Spectroscopic or chromatographic methods used to qualitatively and quantitatively identify the products of the photoreaction. Such devices are usually attached to the photoreactor, or a sample is being trasfered to an identification method via another medium (e.g., gastight syringes)."@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/gas-chromatography>,
-        <http://example.org/nfdi4cat/photo/mass-spectrometry> ;
+    skos:narrower cs:0001059,
+        cs:0001080 ;
     skos:prefLabel "Product identification method"@en .
 
-<http://example.org/nfdi4cat/photo/synthesis-of-photocatalysts> a skos:Concept ;
-    dcterms:identifier "synthesis-of-photocatalysts"^^xsd:token ;
+cs:0001133 a skos:Concept ;
+    dcterms:identifier "photo_0001133"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/photocatalytic-co2-reduction> ;
+    skos:broader cs:0001095 ;
     skos:definition "The process by which one or more chemical reactions are performed with the aim of converting a reactant or starting material into a product or multiple products."@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/literature-research>,
-        <http://example.org/nfdi4cat/photo/synthesis-steps> ;
+    skos:narrower cs:0001075,
+        cs:0001134 ;
     skos:prefLabel "Synthesis of photocatalysts"@en .
 
-<http://example.org/nfdi4cat/photo/thin-film> a skos:Concept ;
-    dcterms:identifier "thin-film"^^xsd:token ;
+cs:0001141 a skos:Concept ;
+    dcterms:identifier "photo_0001141"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/form-of-photocatalyst> ;
+    skos:broader cs:0001057 ;
     skos:definition "A photocatalyst introduced to the reaction chamber in the form of a thin film. To form a thin film, a (powdered) photocatalyst is deposited on a substrate (e.g., glass or metal) using an appropriate deposition technique. "@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/deposited-film>,
-        <http://example.org/nfdi4cat/photo/deposition-technique>,
-        <http://example.org/nfdi4cat/photo/substrate> ;
+    skos:narrower cs:0001025,
+        cs:0001026,
+        cs:0001132 ;
     skos:prefLabel "Thin film"@en .
 
-<http://example.org/nfdi4cat/photo/glass-substrate> a skos:Concept ;
-    dcterms:identifier "glass-substrate"^^xsd:token ;
+cs:0001063 a skos:Concept ;
+    dcterms:identifier "photo_0001063"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/material-of-substrate> ;
+    skos:broader cs:0001084 ;
     skos:definition "A flat surface made of glass serving as a substrate for the deposition of a photocatalyst."@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/borosilicate-glass>,
-        <http://example.org/nfdi4cat/photo/fluorine-doped-tin-oxide-coated-glass>,
-        <http://example.org/nfdi4cat/photo/indium-tin-oxide-coated-glass>,
-        <http://example.org/nfdi4cat/photo/quartz-glass> ;
+    skos:narrower cs:0001007,
+        cs:0001056,
+        cs:0001067,
+        cs:0001110 ;
     skos:prefLabel "Glass substrate"@en .
 
-<http://example.org/nfdi4cat/photo/photocatalytic-co2-reduction> a skos:Concept ;
-    dcterms:identifier "photocatalytic-co2-reduction"^^xsd:token ;
+cs:0001095 a skos:Concept ;
+    dcterms:identifier "photo_0001095"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:altLabel "Photocatalytic carbon dioxide reduction; CO2 photoreduction; Carbon dioxide photoreduction; artificial photosynthesis"@en ;
+    skos:altLabel "CO2 photoreduction"@en,
+        "Carbon dioxide photoreduction"@en,
+        "Photocatalytic carbon dioxide reduction"@en,
+        "artificial photosynthesis"@en ;
     skos:definition "The light-driven reduction (conversion) of carbon dioxide (CO2) to hydrocarbons and / or platform chemicals in presence of water. The absorption of light and the adsorption of the reactants is performed by a photocatalyst (usually a metal oxide). "@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/characterization-of-photocatalysts>,
-        <http://example.org/nfdi4cat/photo/evaluation-of-performance>,
-        <http://example.org/nfdi4cat/photo/photoreactor-design>,
-        <http://example.org/nfdi4cat/photo/synthesis-of-photocatalysts> ;
+    skos:narrower cs:0001013,
+        cs:0001047,
+        cs:0001099,
+        cs:0001133 ;
     skos:prefLabel "Photocatalytic CO2 reduction"@en ;
     skos:topConceptOf cs: .
 
-<http://example.org/nfdi4cat/photo/reactants> a skos:Concept ;
-    dcterms:identifier "reactants"^^xsd:token ;
+cs:0001114 a skos:Concept ;
+    dcterms:identifier "photo_0001114"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/evaluation-of-performance> ;
+    skos:broader cs:0001047 ;
     skos:definition "A substance that is consumed in the course of chemical reaction. It is sometimes knonw, especially in the older literature, as a reagent, but this term is better used in a more specialized sence as a test substance that is added to a system in order to bring about a reaction or to see whether a reaction occurs (e.g., an analytical reagent)."@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/concentration-of-reactants>,
-        <http://example.org/nfdi4cat/photo/flow-rates-of-reactants>,
-        <http://example.org/nfdi4cat/photo/purity-of-reactants>,
-        <http://example.org/nfdi4cat/photo/sacrificial-reagents> ;
+    skos:narrower cs:0001020,
+        cs:0001055,
+        cs:0001109,
+        cs:0001119 ;
     skos:prefLabel "Reactants"@en .
 
-<http://example.org/nfdi4cat/photo/total-duration-of-experiment> a skos:Concept ;
-    dcterms:identifier "total-duration-of-experiment"^^xsd:token ;
+cs:0001142 a skos:Concept ;
+    dcterms:identifier "photo_0001142"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/evaluation-of-performance> ;
+    skos:broader cs:0001047 ;
     skos:definition "The total duration of an experiment"@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/irradiation-time>,
-        <http://example.org/nfdi4cat/photo/purging-time>,
-        <http://example.org/nfdi4cat/photo/sampling-intervals> ;
+    skos:narrower cs:0001071,
+        cs:0001108,
+        cs:0001121 ;
     skos:prefLabel "Total duration of experiment"@en .
 
-<http://example.org/nfdi4cat/photo/wavelength-range> a skos:Concept ;
-    dcterms:identifier "wavelength-range"^^xsd:token ;
+cs:0001152 a skos:Concept ;
+    dcterms:identifier "photo_0001152"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/light-source>,
-        <http://example.org/nfdi4cat/photo/selected-light-source> ;
+    skos:broader cs:0001073,
+        cs:0001123 ;
     skos:definition "Wavelength (single, narrow distribution or range) of the light emmited by the light source."@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/infrared>,
-        <http://example.org/nfdi4cat/photo/ultraviolet>,
-        <http://example.org/nfdi4cat/photo/visible> ;
+    skos:narrower cs:0001068,
+        cs:0001144,
+        cs:0001148 ;
     skos:prefLabel "Wavelength range"@en .
 
-<http://example.org/nfdi4cat/photo/calcination-steps> a skos:Concept ;
-    dcterms:identifier "calcination-steps"^^xsd:token ;
+cs:0001009 a skos:Concept ;
+    dcterms:identifier "photo_0001009"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:altLabel "Heat treatment; Heat-treatment; Calcination"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/synthesis-steps> ;
+    skos:altLabel "Calcination"@en,
+        "Heat treatment"@en,
+        "Heat-treatment"@en ;
+    skos:broader cs:0001134 ;
     skos:definition "Heat treatment to reach the desired final photocatalyst. The parameters of the heat treatment can vary between each calcination step. "@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/dwelling-time>,
-        <http://example.org/nfdi4cat/photo/final-temperature>,
-        <http://example.org/nfdi4cat/photo/gaseous-environment>,
-        <http://example.org/nfdi4cat/photo/heating-rate>,
-        <http://example.org/nfdi4cat/photo/initial-temperature> ;
+    skos:narrower cs:0001038,
+        cs:0001051,
+        cs:0001060,
+        cs:0001065,
+        cs:0001069 ;
     skos:prefLabel "Calcination steps"@en .
 
-<http://example.org/nfdi4cat/photo/gas-chromatography> a skos:Concept ;
-    dcterms:identifier "gas-chromatography"^^xsd:token ;
+cs:0001059 a skos:Concept ;
+    dcterms:identifier "photo_0001059"^^xsd:token ;
     dcterms:provenance "IUPAC"@en ;
     skos:altLabel "GC"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/characterization-of-photocatalysts>,
-        <http://example.org/nfdi4cat/photo/product-identification-method> ;
+    skos:broader cs:0001013,
+        cs:0001107 ;
     skos:definition "A separation technique in which the mobile phase is a gas. Gas chromatography is always carried out in a column."@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/calibration-of-gas-chromatograph>,
-        <http://example.org/nfdi4cat/photo/equipped-detectors-of-gas-chromatograph>,
-        <http://example.org/nfdi4cat/photo/sensitivity-of-gas-chromatograph> ;
+    skos:narrower cs:0001010,
+        cs:0001045,
+        cs:0001126 ;
     skos:prefLabel "Gas chromatography"@en .
 
-<http://example.org/nfdi4cat/photo/operation-mode> a skos:Concept ;
-    dcterms:identifier "operation-mode"^^xsd:token ;
+cs:0001089 a skos:Concept ;
+    dcterms:identifier "photo_0001089"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/evaluation-of-performance>,
-        <http://example.org/nfdi4cat/photo/photoreactor-design> ;
+    skos:broader cs:0001047,
+        cs:0001099 ;
     skos:definition "Operation mode under the which the experiment takes place: batch of continuous flow mode."@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/batch-mode>,
-        <http://example.org/nfdi4cat/photo/flow-mode> ;
+    skos:narrower cs:0001005,
+        cs:0001053 ;
     skos:prefLabel "Operation mode"@en .
 
-<http://example.org/nfdi4cat/photo/reaction-chamber> a skos:Concept ;
-    dcterms:identifier "reaction-chamber"^^xsd:token ;
+cs:0001115 a skos:Concept ;
+    dcterms:identifier "photo_0001115"^^xsd:token ;
     dcterms:provenance "Self"@en ;
     skos:altLabel "Photoreaction chamber"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/photoreactor-design> ;
+    skos:broader cs:0001099 ;
     skos:definition "A construction inside of which the photocatalyst and the reactants coexist and the photoreaction takes place."@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/dimensions-of-reaction-chamber>,
-        <http://example.org/nfdi4cat/photo/material-of-reaction-chamber>,
-        <http://example.org/nfdi4cat/photo/optical-window>,
-        <http://example.org/nfdi4cat/photo/shape-of-reaction-chamber>,
-        <http://example.org/nfdi4cat/photo/volume-of-the-reaction-chamber> ;
+    skos:narrower cs:0001032,
+        cs:0001083,
+        cs:0001090,
+        cs:0001128,
+        cs:0001150 ;
     skos:prefLabel "Reaction chamber"@en .
 
-<http://example.org/nfdi4cat/photo/evaluation-of-performance> a skos:Concept ;
-    dcterms:identifier "evaluation-of-performance"^^xsd:token ;
+cs:0001047 a skos:Concept ;
+    dcterms:identifier "photo_0001047"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/photocatalytic-co2-reduction> ;
+    skos:broader cs:0001095 ;
     skos:definition "Selection of experimental parameters applied for the evaluation of the performance of a photocatalyst in CO2 photoreduction."@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/form-of-photocatalyst>,
-        <http://example.org/nfdi4cat/photo/light-source>,
-        <http://example.org/nfdi4cat/photo/operation-mode>,
-        <http://example.org/nfdi4cat/photo/photocatalytic-co2-reduction-experiment>,
-        <http://example.org/nfdi4cat/photo/reactants>,
-        <http://example.org/nfdi4cat/photo/total-duration-of-experiment> ;
+    skos:narrower cs:0001057,
+        cs:0001073,
+        cs:0001089,
+        cs:0001096,
+        cs:0001114,
+        cs:0001142 ;
     skos:prefLabel "Evaluation of performance"@en .
 
-<http://example.org/nfdi4cat/photo/photocatalytic-co2-reduction-experiment> a skos:Concept ;
-    dcterms:identifier "photocatalytic-co2-reduction-experiment"^^xsd:token ;
+cs:0001096 a skos:Concept ;
+    dcterms:identifier "photo_0001096"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:altLabel "Carbon dioxide photoreduction experiment; Photocatalytic CO2 reduction experiment; Photocatalytic carbon dioxide reduction experiment"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/evaluation-of-performance> ;
+    skos:altLabel "Carbon dioxide photoreduction experiment"@en,
+        "Photocatalytic CO2 reduction experiment"@en,
+        "Photocatalytic carbon dioxide reduction experiment"@en ;
+    skos:broader cs:0001047 ;
     skos:definition "An experiment in which a photocatalyst in the presence of H2O and under the influence of light of appropriate wavelength, converts CO2 to hydrocarbons and / or useful platform chemicals. "@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/blank-measurements>,
-        <http://example.org/nfdi4cat/photo/co2-photoreduction-measurement>,
-        <http://example.org/nfdi4cat/photo/evaluation-of-products-formed>,
-        <http://example.org/nfdi4cat/photo/pressure-drop-in-a-co2-phoreduction-experiment>,
-        <http://example.org/nfdi4cat/photo/pressure-in-a-co2-photoreduction-experiment>,
-        <http://example.org/nfdi4cat/photo/sample-pre-treatment>,
-        <http://example.org/nfdi4cat/photo/selectivity> ;
+    skos:narrower cs:0001006,
+        cs:0001018,
+        cs:0001048,
+        cs:0001104,
+        cs:0001105,
+        cs:0001120,
+        cs:0001124 ;
     skos:prefLabel "Photocatalytic CO2 reduction experiment"@en .
 
-<http://example.org/nfdi4cat/photo/photoreactor-design> a skos:Concept ;
-    dcterms:identifier "photoreactor-design"^^xsd:token ;
+cs:0001099 a skos:Concept ;
+    dcterms:identifier "photo_0001099"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:altLabel "Reactor design; Reactor engineering; Photoreactor engineering"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/photocatalytic-co2-reduction> ;
+    skos:altLabel "Photoreactor engineering"@en,
+        "Reactor design"@en,
+        "Reactor engineering"@en ;
+    skos:broader cs:0001095 ;
     skos:definition "Details describing the construction, physical dimensions, and operation of the photoreactor used for the photocalytic CO2 reduction reactions."@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/gas-flow>,
-        <http://example.org/nfdi4cat/photo/light-source>,
-        <http://example.org/nfdi4cat/photo/operation-mode>,
-        <http://example.org/nfdi4cat/photo/product-identification-method>,
-        <http://example.org/nfdi4cat/photo/range-of-operation-temperature>,
-        <http://example.org/nfdi4cat/photo/reaction-chamber> ;
+    skos:narrower cs:0001061,
+        cs:0001073,
+        cs:0001089,
+        cs:0001107,
+        cs:0001113,
+        cs:0001115 ;
     skos:prefLabel "Photoreactor design"@en .
 
-<http://example.org/nfdi4cat/photo/synthesis-steps> a skos:Concept ;
-    dcterms:identifier "synthesis-steps"^^xsd:token ;
+cs:0001134 a skos:Concept ;
+    dcterms:identifier "photo_0001134"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/synthesis-of-photocatalysts> ;
+    skos:broader cs:0001133 ;
     skos:definition "Necessary steps needed to follow in order to reach the desired photocatalyst."@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/calcination-steps>,
-        <http://example.org/nfdi4cat/photo/duration-of-steps>,
-        <http://example.org/nfdi4cat/photo/equipment-used-for-synthesis>,
-        <http://example.org/nfdi4cat/photo/ph-in-synthesis>,
-        <http://example.org/nfdi4cat/photo/pressure-in-synthesis>,
-        <http://example.org/nfdi4cat/photo/temperature-in-synthesis> ;
+    skos:narrower cs:0001009,
+        cs:0001037,
+        cs:0001044,
+        cs:0001093,
+        cs:0001106,
+        cs:0001136 ;
     skos:prefLabel "Synthesis steps"@en .
 
-<http://example.org/nfdi4cat/photo/light-source> a skos:Concept ;
-    dcterms:identifier "light-source"^^xsd:token ;
+cs:0001073 a skos:Concept ;
+    dcterms:identifier "photo_0001073"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/evaluation-of-performance>,
-        <http://example.org/nfdi4cat/photo/photoreactor-design> ;
+    skos:broader cs:0001047,
+        cs:0001099 ;
     skos:definition "Light sources used to irradiate a photocatalyst. These include sources with various intensities, powers and wavelength ranges,  including Hg/Xe lamps, Xe lamps and LEDs. "@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/current-of-operation-of-the-light-source>,
-        <http://example.org/nfdi4cat/photo/distance-of-light-source-from-the-reaction-chamber-sample>,
-        <http://example.org/nfdi4cat/photo/intensity-of-the-light-source>,
-        <http://example.org/nfdi4cat/photo/power-output-of-the-light-source>,
-        <http://example.org/nfdi4cat/photo/voltage-of-operation-of-the-light-source>,
-        <http://example.org/nfdi4cat/photo/wavelength-range> ;
+    skos:narrower cs:0001023,
+        cs:0001034,
+        cs:0001070,
+        cs:0001102,
+        cs:0001149,
+        cs:0001152 ;
     skos:prefLabel "Light source"@en .
 
-<http://example.org/nfdi4cat/photo/characterization-of-photocatalysts> a skos:Concept ;
-    dcterms:identifier "characterization-of-photocatalysts"^^xsd:token ;
+cs:0001013 a skos:Concept ;
+    dcterms:identifier "photo_0001013"^^xsd:token ;
     dcterms:provenance "Self"@en ;
-    skos:broader <http://example.org/nfdi4cat/photo/photocatalytic-co2-reduction> ;
+    skos:broader cs:0001095 ;
     skos:definition "A collection of techniques used to identify the (physico)chemical, morphological, structural, mechanical, optical and electrical properties of the syntesized photocatalysts. Characterization is performed after the synthesis of the photocatalysts to evaluate the success of the synthetic approach, but also after the completion of the evaluation of the materials in CO2 photoreduction to ensure their stability under the selected experimental parameters."@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/atomic-force-microscopy>,
-        <http://example.org/nfdi4cat/photo/brunauer-emmett-teller-surface-area-analysis>,
-        <http://example.org/nfdi4cat/photo/cyclic-voltammetry>,
-        <http://example.org/nfdi4cat/photo/differential-scanning-calorimetry>,
-        <http://example.org/nfdi4cat/photo/electron-energy-loss-spectroscopy>,
-        <http://example.org/nfdi4cat/photo/fourier-transform-infrared-spectroscopy>,
-        <http://example.org/nfdi4cat/photo/gas-chromatography>,
-        <http://example.org/nfdi4cat/photo/liquid-chromatography>,
-        <http://example.org/nfdi4cat/photo/mass-spectroscopy>,
-        <http://example.org/nfdi4cat/photo/mott-schottky-analysis>,
-        <http://example.org/nfdi4cat/photo/nuclear-magnetic-resonance-spectroscopy>,
-        <http://example.org/nfdi4cat/photo/photoluminescence>,
-        <http://example.org/nfdi4cat/photo/raman-spectroscopy>,
-        <http://example.org/nfdi4cat/photo/scanning-electron-microscopy>,
-        <http://example.org/nfdi4cat/photo/thermogravimetric-analysis>,
-        <http://example.org/nfdi4cat/photo/transmission-electron-microscopy>,
-        <http://example.org/nfdi4cat/photo/ultraviolet-visible-spectroscopy>,
-        <http://example.org/nfdi4cat/photo/x-ray-diffraction>,
-        <http://example.org/nfdi4cat/photo/x-ray-fluorescence>,
-        <http://example.org/nfdi4cat/photo/x-ray-photoelectron-spectroscopy> ;
+    skos:narrower cs:0001003,
+        cs:0001008,
+        cs:0001024,
+        cs:0001029,
+        cs:0001039,
+        cs:0001058,
+        cs:0001059,
+        cs:0001074,
+        cs:0001081,
+        cs:0001087,
+        cs:0001088,
+        cs:0001098,
+        cs:0001111,
+        cs:0001122,
+        cs:0001138,
+        cs:0001143,
+        cs:0001145,
+        cs:0001153,
+        cs:0001154,
+        cs:0001155 ;
     skos:prefLabel "Characterization of photocatalysts"@en .
 
-<http://example.org/nfdi4cat/photo/general-terms> a skos:Concept ;
-    dcterms:identifier "general-terms"^^xsd:token ;
+cs:0001062 a skos:Concept ;
+    dcterms:identifier "photo_0001062"^^xsd:token ;
     dcterms:provenance "Self"@en ;
     skos:definition "General terms often used in the field of photocatalysis."@en ;
     skos:inScheme cs: ;
-    skos:narrower <http://example.org/nfdi4cat/photo/absorption>,
-        <http://example.org/nfdi4cat/photo/bandgap-energy>,
-        <http://example.org/nfdi4cat/photo/charge-photogeneration>,
-        <http://example.org/nfdi4cat/photo/charge-recombination>,
-        <http://example.org/nfdi4cat/photo/charge-separation>,
-        <http://example.org/nfdi4cat/photo/conduction-band>,
-        <http://example.org/nfdi4cat/photo/crystallinity>,
-        <http://example.org/nfdi4cat/photo/doping>,
-        <http://example.org/nfdi4cat/photo/electron-transfer>,
-        <http://example.org/nfdi4cat/photo/excited-state>,
-        <http://example.org/nfdi4cat/photo/fermi-level>,
-        <http://example.org/nfdi4cat/photo/ground-state>,
-        <http://example.org/nfdi4cat/photo/hole-transfer>,
-        <http://example.org/nfdi4cat/photo/infrared>,
-        <http://example.org/nfdi4cat/photo/metal-oxide>,
-        <http://example.org/nfdi4cat/photo/oxidation>,
-        <http://example.org/nfdi4cat/photo/photocatalyst>,
-        <http://example.org/nfdi4cat/photo/photoexcitation>,
-        <http://example.org/nfdi4cat/photo/pore-size-distribution>,
-        <http://example.org/nfdi4cat/photo/reduction>,
-        <http://example.org/nfdi4cat/photo/semiconductor>,
-        <http://example.org/nfdi4cat/photo/specific-surface-area>,
-        <http://example.org/nfdi4cat/photo/ultraviolet>,
-        <http://example.org/nfdi4cat/photo/valence-band>,
-        <http://example.org/nfdi4cat/photo/visible>,
-        <http://example.org/nfdi4cat/photo/wavelength> ;
+    skos:narrower cs:0001001,
+        cs:0001004,
+        cs:0001014,
+        cs:0001015,
+        cs:0001016,
+        cs:0001021,
+        cs:0001022,
+        cs:0001036,
+        cs:0001040,
+        cs:0001049,
+        cs:0001050,
+        cs:0001064,
+        cs:0001066,
+        cs:0001068,
+        cs:0001086,
+        cs:0001092,
+        cs:0001094,
+        cs:0001097,
+        cs:0001100,
+        cs:0001116,
+        cs:0001125,
+        cs:0001129,
+        cs:0001144,
+        cs:0001147,
+        cs:0001148,
+        cs:0001151 ;
     skos:prefLabel "General terms"@en ;
     skos:topConceptOf cs: .
 
 cs: a skos:ConceptScheme ;
     dcterms:created "2022-04-13"^^xsd:date ;
     dcterms:creator <https://www.catalysis.de/> ;
-    dcterms:hasPart <http://example.org/nfdi4cat/photo/characterization-of-photocatalysts-coll>,
-        <http://example.org/nfdi4cat/photo/evaluation-of-performance-coll>,
-        <http://example.org/nfdi4cat/photo/general-terms-coll>,
-        <http://example.org/nfdi4cat/photo/photocatalytic-co2-reduction-coll>,
-        <http://example.org/nfdi4cat/photo/reactor-design-coll>,
-        <http://example.org/nfdi4cat/photo/synthesis-of-photocatalysts-coll> ;
-    dcterms:identifier "photo"^^xsd:token ;
+    dcterms:hasPart cs:0001156,
+        cs:0001157,
+        cs:0001158,
+        cs:0001159,
+        cs:0001160,
+        cs:0001161 ;
+    dcterms:identifier "photo_"^^xsd:token ;
     dcterms:modified "2022-04-13"^^xsd:date ;
     dcterms:provenance "Heterogene Photokatalyse / Leibniz Institute für Katalyse e.V. (LIKAT)"@en ;
     dcterms:publisher <http://example.org/nfdi4cat/> ;
     owl:versionInfo "0.1" ;
     skos:definition "A vocabulary of the most commonly used terms in the heterogeneous photocatalytic (light-driven) reduction (conversion) of carbon dioxide (CO2) to hydrocarbons and / or platform chemicals"@en ;
-    skos:hasTopConcept <http://example.org/nfdi4cat/photo/chemical-substances-used-for-synthesis>,
-        <http://example.org/nfdi4cat/photo/flow-mode-co2-reduction-experiment>,
-        <http://example.org/nfdi4cat/photo/general-terms>,
-        <http://example.org/nfdi4cat/photo/photocatalytic-co2-reduction>,
-        <http://example.org/nfdi4cat/photo/range-of-operation-pressure>,
-        <http://example.org/nfdi4cat/photo/selected-light-source>,
-        <http://example.org/nfdi4cat/photo/temperature-in-a-co2-photoreduction-experiment> ;
+    skos:hasTopConcept cs:0001017,
+        cs:0001062,
+        cs:0001095,
+        cs:0001112,
+        cs:0001123,
+        cs:0001135 ;
     skos:prefLabel "Photocatalytic CO2 reduction"@en ;
     dcat:contactPoint "Nikolaos Moustakas / David Linke / Jennifer Strunk" .
 
diff --git a/example/Photocatalysis_LIKAT_template043_final.xlsx b/example/Photocatalysis_LIKAT_template043_final.xlsx
index 8413cd5..a2600a7 100644
Binary files a/example/Photocatalysis_LIKAT_template043_final.xlsx and b/example/Photocatalysis_LIKAT_template043_final.xlsx differ
diff --git a/example/Photocatalysis_LIKAT_template043_indent_iri.xlsx b/example/Photocatalysis_LIKAT_template043_from-indent.xlsx
similarity index 54%
rename from example/Photocatalysis_LIKAT_template043_indent_iri.xlsx
rename to example/Photocatalysis_LIKAT_template043_from-indent.xlsx
index 2e7cd7d..9908eb5 100644
Binary files a/example/Photocatalysis_LIKAT_template043_indent_iri.xlsx and b/example/Photocatalysis_LIKAT_template043_from-indent.xlsx differ
diff --git a/example/Photocatalysis_LIKAT_template043_from-indent_final.xlsx b/example/Photocatalysis_LIKAT_template043_from-indent_final.xlsx
new file mode 100644
index 0000000..1297aed
Binary files /dev/null and b/example/Photocatalysis_LIKAT_template043_from-indent_final.xlsx differ
diff --git a/example/Photocatalysis_LIKAT_template043_indent.xlsx b/example/Photocatalysis_LIKAT_template043_indent.xlsx
index c8084a5..f2edb64 100644
Binary files a/example/Photocatalysis_LIKAT_template043_indent.xlsx and b/example/Photocatalysis_LIKAT_template043_indent.xlsx differ
diff --git a/example/Photocatalysis_LIKAT_template043_indent_formula.xlsx b/example/Photocatalysis_LIKAT_template043_indent_formula.xlsx
new file mode 100644
index 0000000..6418321
Binary files /dev/null and b/example/Photocatalysis_LIKAT_template043_indent_formula.xlsx differ
diff --git a/example/Photocatalysis_LIKAT_template043_orig-fixed.xlsx b/example/Photocatalysis_LIKAT_template043_orig-fixed.xlsx
index d81395f..91c82b5 100644
Binary files a/example/Photocatalysis_LIKAT_template043_orig-fixed.xlsx and b/example/Photocatalysis_LIKAT_template043_orig-fixed.xlsx differ
diff --git a/example/Photocatalysis_LIKAT_template043_textids.xlsx b/example/Photocatalysis_LIKAT_template043_textids.xlsx
new file mode 100644
index 0000000..f71b866
Binary files /dev/null and b/example/Photocatalysis_LIKAT_template043_textids.xlsx differ
diff --git a/example/README.md b/example/README.md
index 08b71a9..111a4da 100644
--- a/example/README.md
+++ b/example/README.md
@@ -2,23 +2,25 @@ Example files showing what voc4cat can do:
 
 - `Photocatalysis_LIKAT_template043_orig-fixed.xlsx`
   - A draft of a photocatalysis vocabulary: This has still the original structure and contents; only spelling and link errors were fixed.
-  - The hierarchy was created by the now removed `-r` / `--add-related` option from the extra column on the right in sheets Concepts & Collections. These columns are not part of the standard template.
+  - The hierarchy was created with voc4cat 0.30 by the `-r` / `--add-related` option from the extra column on the right in sheets Concepts & Collections. Note, this option was removed in 0.4.0 to foster using numeric IDs.
+- `Photocatalysis_LIKAT_template043_textids.xlsx`
+  - Same contents as the first file but the extra column in the sheets Concepts & Collections was removed. The concepts were sorted by IRI (this was done to assign IDs in a reproducible way to domonstrate round-tripping, see below).
 - `Photocatalysis_LIKAT_template043_final.xlsx`
-  - Same contents as the first file but the extra column in the sheets Concepts & Collections was removed.
+  - This file was generate from the previous one by replacing the textual IDs with numeric ones using the `--make-ids` option added in version 0.4.0.
 - `Photocatalysis_LIKAT_template043_final.ttl`
   - Results of processing the previous file with voc4cat without options (which does convert to turtle).
 
-The above example is not representing the most typical workflow.
-In practise one would start creating vocabularies from a file that does not yet have IRIs.
-In this case hierarchies have to be expressed by indentation:
+The above example may not represent the most typical workflow.
+In practice one would start creating vocabularies from a file that does not yet have IRIs.
+In this case hierarchies may be expressed by indentation:
 
 - `Photocatalysis_LIKAT_template043_indent.xlsx`
-  - Same content as first file, but it uses Excel indentation to express hierarchy and does not contain IRIs for concepts.
-- `Photocatalysis_LIKAT_template043_indent_iri.xlsx`
-  - This results from processing the previous file with voc4cat using the `-i` / `--add-iri` option.
-- `Photocatalysis_LIKAT_template043_indent_final.xlsx`
-  - This results from processing the previous file with voc4cat using the `--hierarchy-from-indent` option.
-  - If this file is futher processed with voc4cat without options, a turtle file is generated that is identical to the turtle file from above (`Photocatalysis_LIKAT_template043_final.ttl`) - So round-tripping does work!
+  - Same content as first file, but it uses Excel indentation to express hierarchy. It does contain temporary IRIs for concepts created from the preferred label with Excel functions.
+- `Photocatalysis_LIKAT_template043_from-indent.xlsx`
+  - This results from processing the previous file with voc4cat using the `--hierarchy-from-indent` option. The concepts were sorted by IRI (like above).
+- `Photocatalysis_LIKAT_template043_from-indent_final.xlsx`
+  - This results from processing the previous file with voc4cat using the `--make-ids new 1001` option which replaces the temporary IRIs with IRIs containing  numeric IDs.
+  - If this file is further processed with voc4cat without options, a turtle file is generated that is identical to the turtle file from above. - So round-tripping does work!
 
 Files demonstrating the different ways how to express concept-hierarchies:
 
diff --git a/example/concept_hierarchy_043_4Cat.xlsx b/example/concept_hierarchy_043_4Cat.xlsx
index 9b9ab6a..83d3a81 100644
Binary files a/example/concept_hierarchy_043_4Cat.xlsx and b/example/concept_hierarchy_043_4Cat.xlsx differ
diff --git a/example/indent_043_4Cat.xlsx b/example/indent_043_4Cat.xlsx
index 643764b..8d12de3 100644
Binary files a/example/indent_043_4Cat.xlsx and b/example/indent_043_4Cat.xlsx differ
diff --git a/example/indent_3spaces_043_4Cat.xlsx b/example/indent_3spaces_043_4Cat.xlsx
index 447aa18..c32da0c 100644
Binary files a/example/indent_3spaces_043_4Cat.xlsx and b/example/indent_3spaces_043_4Cat.xlsx differ
diff --git a/inbox-excel-vocabs/README.md b/inbox-excel-vocabs/README.md
deleted file mode 100644
index 27236eb..0000000
--- a/inbox-excel-vocabs/README.md
+++ /dev/null
@@ -1,1 +0,0 @@
-Please drop your filled out VocExcel-templates into this folder and create a merge request.
diff --git a/pyproject.toml b/pyproject.toml
index 8785b4b..6c9abb1 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -7,7 +7,7 @@ build-backend = "hatchling.build"
 [project]
 # Storing project metadata in pyproject.toml https://peps.python.org/pep-0621/
 name = "voc4cat"
-description = "Vocabulary management for NFDI4Cat."
+description = "SKOS vocabulary management tool of NFDI4Cat."
 authors = [
     {name = "David Linke", email = "david.linke@catalysis.de"}
 ]
@@ -28,11 +28,12 @@ classifiers = [
   "Programming Language :: Python :: 3.8",
   "Programming Language :: Python :: 3.9",
   "Programming Language :: Python :: 3.10",
+  "Programming Language :: Python :: 3.11",
 ]
 
 dependencies = [
   # install vocexcel directly from a specific branch from github
-  "vocexcel @ git+https://github.com/nfdi4cat/VocExcel.git@nfdi4cat-dev",
+  "vocexcel @ git+https://github.com/nfdi4cat/VocExcel.git@nfdi4cat-main",
   "networkx >= 2.8",
   "openpyxl >= 3.0.9",
   "pillow >= 9.1.0",
@@ -43,10 +44,10 @@ dependencies = [
 dynamic = ["version"]
 
 [project.urls]
-homepage = "https://gitlab.fokus.fraunhofer.de/nfdi4cat/ta1-ontologies/voc4cat-tool/"
-repository = "https://gitlab.fokus.fraunhofer.de/nfdi4cat/ta1-ontologies/voc4cat-tool/"
-documentation = "https://gitlab.fokus.fraunhofer.de/nfdi4cat/ta1-ontologies/voc4cat-tool/"
-# changelog = "https://gitlab.fokus.fraunhofer.de/nfdi4cat/ta1-ontologies/voc4cat-tool/CHANGELOG.md"
+homepage = "https://github.com/nfdi4cat/voc4cat-tool/"
+repository = "https://github.com/nfdi4cat/voc4cat-tool/"
+documentation = "https://github.com/nfdi4cat/voc4cat-tool/"
+changelog = "https://github.com/nfdi4cat/voc4cat-tool/CHANGELOG.md"
 
 [project.optional-dependencies]
 tests = [
@@ -164,6 +165,6 @@ exclude_lines = [
 ]
 
 [tool.coverage.html]
-# directory where to write the HTML report files.
+# Directory where to write the HTML report files.
 directory = ".htmlcov"
 title = "voc4cat coverage report"
diff --git a/src/voc4cat/wrapper.py b/src/voc4cat/wrapper.py
index 457ce0a..feffa04 100644
--- a/src/voc4cat/wrapper.py
+++ b/src/voc4cat/wrapper.py
@@ -1,18 +1,13 @@
 # -*- coding: utf-8 -*-
-"""
-A wrapper to extend VocExcel with more commands.
+"""A wrapper to extend VocExcel with more commands."""
 
-The new commands may be run either before or after VocExcel.
-
-Copyright (c) 2022 David Linke (ORCID: 0000-0002-5898-1820)
-"""
 import argparse
 import datetime
 import glob
 import os
 import sys
 from collections import defaultdict
-from itertools import count
+from itertools import count, zip_longest
 from pathlib import Path
 from warnings import warn
 
@@ -73,7 +68,8 @@ def is_supported_template(wb):
 def may_overwrite(no_warn, xlf, outfile, func):
     if not no_warn and os.path.exists(outfile) and Path(xlf) == Path(outfile):
         warn(
-            f'Option "--{func.__name__.replace("_", "-")}" will overwrite the existing file {outfile}\n'
+            f'Option "--{func.__name__.replace("_", "-")}" '
+            f"will overwrite the existing file {outfile}\n"
             "Run again with --no-warn option to overwrite the file."
         )
         return False
@@ -99,14 +95,13 @@ def make_ids(fpath, outfile, search_prefix, start_id):
     If new_prefix is given the new IRI is the CURI new_prefix:ID.
     """
     print(f"\nReplacing {search_prefix}:... IRIs.")
-    wb = openpyxl.load_workbook(fpath)
+    # Load in data_only mode to get cell values not formulas.
+    wb = openpyxl.load_workbook(fpath, data_only=True)
     is_supported_template(wb)
     VOC_BASE_IRI = wb["Concept Scheme"].cell(row=2, column=2).value
     if VOC_BASE_IRI is None:
         VOC_BASE_IRI = "https://example.org/"
         wb["Concept Scheme"].cell(row=2, column=2).value = VOC_BASE_IRI
-    if not VOC_BASE_IRI.endswith("/"):
-        VOC_BASE_IRI += "/"
 
     try:
         start_id = int(start_id)
@@ -126,37 +121,41 @@ def make_ids(fpath, outfile, search_prefix, start_id):
         for row in ws.iter_rows(min_row=3, max_col=2):  # pragma: no branch
             if row[0].value:
                 iri = str(row[0].value)
-                if iri.startswith(search_prefix):
-                    iri_new = VOC_BASE_IRI + str(next(id_gen))
+                if not iri.startswith(search_prefix):
+                    continue
+                if iri in replaced_iris:
+                    iri_new = replaced_iris[iri]
+                else:
+                    iri_new = VOC_BASE_IRI + f"{next(id_gen):07d}"
                     print(f"[{sheet}] Replaced CURI {iri} by {iri_new}")
                     replaced_iris[iri] = iri_new
-                    row[0].value = iri_new
+                row[0].value = iri_new
 
     # replace iri by new_iri in all columns where it might be referenced
     cols_to_update = {
         "Concepts": [6],
         "Collections": [3],
-        "Additional Concept Features": [1, 2, 3, 4, 5],
+        "Additional Concept Features": [0, 1, 2, 3, 4, 5],
     }
     for sheet, cols in cols_to_update.items():
-        subsequent_empty_rows = 0
         ws = wb[sheet]
         # iterate over first two columns; skip header and start from row 3
         for row in ws.iter_rows(min_row=3, max_col=1 + max(cols)):  # pragma: no branch
             # stop processing a sheet after 3 empty rows
-            if subsequent_empty_rows < 3:
-                subsequent_empty_rows += 1
-            else:
-                break
             for col in cols:
                 if row[col].value:
                     iris = [iri.strip() for iri in str(row[col].value).split(",")]
-                    new_iris = [replaced_iris.get(iri, iri) for iri in iris]
-                    print(
-                        f"[{sheet}] Replaced {len(new_iris)} CURIs in cell {row[col].coordinate}"
+                    count_new_iris = [1 for iri in iris if iri in replaced_iris].count(
+                        1
                     )
-                    row[col].value = ", ".join(new_iris)
-                    subsequent_empty_rows = 0
+                    if count_new_iris:
+                        new_iris = [replaced_iris.get(iri, iri) for iri in iris]
+                        print(
+                            f"[{sheet}] Replaced {count_new_iris} CURIs "
+                            f"in cell {row[col].coordinate}"
+                        )
+                        row[col].value = ", ".join(new_iris)
+                    # subsequent_empty_rows = 0
 
     wb.save(outfile)
     print(f"Saved updated file as {outfile}")
@@ -171,7 +170,8 @@ def hierarchy_from_indent(fpath, outfile, sep):
     Excel indent which is also the default if sep is None.
     """
     print(f"\nReading concepts from file {fpath}")
-    wb = openpyxl.load_workbook(fpath)
+    # Load in data_only mode to get cell values not formulas.
+    wb = openpyxl.load_workbook(fpath, data_only=True)
     is_supported_template(wb)
     # process both worksheets
     subsequent_empty_rows = 0
@@ -205,8 +205,7 @@ def hierarchy_from_indent(fpath, outfile, sep):
                 ]
                 old_data = row_by_iri[iri].get(lang, [None] * (len(new_data)))
                 merged = []
-                labels = ["ChildrenIRI", "Provenance", "SourceVocabURL"]
-                for old, new, label in zip(old_data, new_data, labels):
+                for old, new in zip(old_data, new_data, strict=True):
                     if (old and new) and (old != new):
                         raise ValueError(
                             f"Cannot merge rows for {iri}. "
@@ -236,7 +235,9 @@ def hierarchy_from_indent(fpath, outfile, sep):
     for iri in children_by_iri:
         for lang in row_by_iri[iri]:
             ws.cell(row, column=1).value = iri
-            for col, stored_value in zip(range(2, col_last), row_by_iri[iri][lang]):
+            for col, stored_value in zip_longest(
+                range(2, col_last), row_by_iri[iri][lang]
+            ):
                 ws.cell(row, column=col).value = stored_value
             ws.cell(row, column=col_children_iri).value = ", ".join(
                 children_by_iri[iri]
@@ -289,11 +290,10 @@ def hierarchy_to_indent(fpath, outfile, sep):
                 new_data = [row[col_no] for col_no in range(6, col_last)]
                 old_data = row_by_iri[iri][list(row_by_iri[iri].keys())[0]][5:]
                 merged = []
-                labels = ["ChildrenIRI", "Provenance", "SourceVocabURL"]
-                for old, new, label in zip(old_data, new_data, labels):
+                for old, new in zip(old_data, new_data):
                     if (old and new) and (old != new):
                         raise ValueError(
-                            f"Merge conflict for concept {iri} in column {label}. "
+                            f"Merge conflict for concept {iri}. "
                             f'New: "{new}" - Before: "{old}"'
                         )
                     merged.append(old if old else new)
@@ -334,19 +334,19 @@ def hierarchy_to_indent(fpath, outfile, sep):
             ws.cell(row, 3).value = lang
 
             if (iri, lang) in iri_written:  # case 2
-                for col, stored_value in zip(
+                for col, stored_value in zip_longest(
                     range(4, col_last + 1), row_by_iri[iri][lang][2:]
                 ):
-                    ws.cell(ws.cell(row, 1).row, column=col).value = None
+                    ws.cell(row, column=col).value = None
                 row += 1
                 continue
             else:
-                for col, stored_value in zip(
+                for col, stored_value in zip_longest(
                     range(4, col_last + 1), row_by_iri[iri][lang][2:]
                 ):
-                    ws.cell(ws.cell(row, 1).row, column=col).value = stored_value
+                    ws.cell(row, column=col).value = stored_value
             # clear children IRI column G
-            ws.cell(ws.cell(row, 1).row, column=7).value = None
+            ws.cell(row, column=7).value = None
             row += 1
             iri_written.append((iri, lang))
 
@@ -478,7 +478,8 @@ def main_cli(args=None):
         "--make-ids",
         help=(
             "Specify prefix to search and replace by ID-based vocabulary IRIs. "
-            "The prefix and the start ID (positive interger) are required."
+            "The prefix and a start ID (positive integer) are required."
+            "The IDs have a length of 7 and are left padded with 0 if shorter."
         ),
         nargs=2,
         metavar=("prefix", "start-ID"),
diff --git a/templates/VocExcel-template_043_4Cat.xlsx b/templates/VocExcel-template_043_4Cat.xlsx
index d9e6694..c428649 100644
Binary files a/templates/VocExcel-template_043_4Cat.xlsx and b/templates/VocExcel-template_043_4Cat.xlsx differ


Test patch:
diff --git a/tests/data/concept-scheme-simple.xlsx b/tests/data/concept-scheme-simple.xlsx
index 717fdef..39278ae 100644
Binary files a/tests/data/concept-scheme-simple.xlsx and b/tests/data/concept-scheme-simple.xlsx differ
diff --git a/tests/data/concept-scheme-with-cycles_multilang.xlsx b/tests/data/concept-scheme-with-cycles_multilang.xlsx
index fb2af36..a8da276 100644
Binary files a/tests/data/concept-scheme-with-cycles_multilang.xlsx and b/tests/data/concept-scheme-with-cycles_multilang.xlsx differ
diff --git a/tests/data/concept-scheme-with-cycles_multilang_indent_iri.xlsx b/tests/data/concept-scheme-with-cycles_multilang_indent_iri.xlsx
index ba5ef15..38b982e 100644
Binary files a/tests/data/concept-scheme-with-cycles_multilang_indent_iri.xlsx and b/tests/data/concept-scheme-with-cycles_multilang_indent_iri.xlsx differ
diff --git a/tests/test_wrapper.py b/tests/test_wrapper.py
index e4ac95e..046a47c 100644
--- a/tests/test_wrapper.py
+++ b/tests/test_wrapper.py
@@ -110,18 +110,18 @@ def test_make_ids_invalid_id(datadir):
 def test_make_ids_variants(datadir, tmp_path, indir, outdir):
     # fmt: off
     expected_concepts = [
-        ("ex:test/1001", "term1", "en", "def for term1", "en", "AltLbl for term1", "ex:test/1002, ex:test/1003",),  # noqa:E501
-        ("ex:test/1002", "term2", "en", "def for term2", "en", "AltLbl for term2", None,),  # noqa:E501
-        ("ex:test/1003", "term3", "en", "def for term3", "en", "AltLbl for term3", "ex:test/1004",),  # noqa:E501
-        ("ex:test/1004", "term4", "en", "def for term4", "en", "AltLbl for term4", None, ),  # noqa:E501
-        ("ex:test/1005", "term5", "en", "def for term5", "en", "AltLbl for term5", None, ),  # noqa:E501
-        ("ex:test/1006", "term6", "en", "def for term6", "en", "AltLbl for term6", None,),  # noqa:E501
+        ("ex:test/0001001", "term1", "en", "def for term1", "en", "AltLbl for term1", "ex:test/0001002, ex:test/0001003",),  # noqa:E501
+        ("ex:test/0001002", "term2", "en", "def for term2", "en", "AltLbl for term2", None,),  # noqa:E501
+        ("ex:test/0001003", "term3", "en", "def for term3", "en", "AltLbl for term3", "ex:test/0001004",),  # noqa:E501
+        ("ex:test/0001004", "term4", "en", "def for term4", "en", "AltLbl for term4", None, ),  # noqa:E501
+        ("ex:test/0001005", "term5", "en", "def for term5", "en", "AltLbl for term5", None, ),  # noqa:E501
+        ("ex:test/0001006", "term6", "en", "def for term6", "en", "AltLbl for term6", None,),  # noqa:E501
     ]
     expected_collections = [
-        ("ex:test/1007", "con", "def for con", "ex:test/1001, ex:test/1002, ex:test/1003, ex:test/1004",),  # noqa:E501
+        ("ex:test/0001007", "con", "def for con", "ex:test/0001001, ex:test/0001002, ex:test/0001003, ex:test/0001004",),  # noqa:E501
     ]
     expected_additional = [
-        (None, "ex:test/1002", "ex:test/1003", "ex:test/1004", "ex:test/1005", "ex:test/1006", ),  # noqa:E501
+        ("ex:test/0001001", "ex:test/0001002", "ex:test/0001003", "ex:test/0001004", "ex:test/0001005", "ex:test/0001006", ),  # noqa:E501
     ]
     # fmt: on
     shutil.copy(datadir / CS_SIMPLE, tmp_path)
@@ -153,6 +153,30 @@ def test_make_ids_variants(datadir, tmp_path, indir, outdir):
         assert row == expected_row
 
 
+def test_make_ids_multilang(tmp_path, datadir):
+    # fmt: off
+    expected_concepts = [
+        ("ex:test/0001001", "term1", "en", "def for term1", "en", "AltLbl for term1", "ex:test/0001002, ex:test/0001003",),  # noqa:E501
+        ("ex:test/0001002", "term2", "en", "def for term2", "en", "AltLbl for term2", "ex:test/0001004",),  # noqa:E501
+        ("ex:test/0001003", "term3", "en", "def for term3", "en", "AltLbl for term3", "ex:test/0001004",),  # noqa:E501
+        ("ex:test/0001004", "term4", "en", "def for term4", "en", "AltLbl for term4", None, ),  # noqa:E501
+        ('ex:test/0001004', 'Begr4', 'de', 'Def für Begr4', 'de', 'AltLbl für Begr4', None, ),  # noqa:E501
+        ('ex:test/0001001', 'Begr1', 'de', 'Def für Begr1', 'de', 'AltLbl für Begr1', None, ),  # noqa:E501
+    ]
+    # fmt: on
+    main_cli(
+        ["--make-ids", "ex", "1001", "--output-directory"]
+        + [str(tmp_path), str(datadir / CS_CYCLES_MULTI_LANG)]
+    )
+    xlsxfile = tmp_path / CS_CYCLES_MULTI_LANG
+    wb = load_workbook(filename=xlsxfile, read_only=True, data_only=True)
+    ws = wb["Concepts"]
+    for row, expected_row in zip(
+        ws.iter_rows(min_row=3, max_col=7, values_only=True), expected_concepts
+    ):
+        assert row == expected_row
+
+
 def test_hierarchy_from_indent_on_dir(tmp_path, capsys):
     exit_code = main_cli(["--hierarchy-from-indent", str(tmp_path / "missing.xlsx")])
     captured = capsys.readouterr()
@@ -208,7 +232,6 @@ def test_hierarchy_from_indent_multilang(datadir, tmp_path):
     expected = [  # data in children-IRI-representation
         ('ex:test/term1', 'term1', 'en', 'def for term1', 'en', 'AltLbl for term1', 'ex:test/term2, ex:test/term3', 'Prov for term1', 'ex:XYZ/term1'),  # noqa:E501
         ('ex:test/term1', 'Begr1', 'de', 'Def für Begr1', 'de', 'AltLbl für Begr1', 'ex:test/term2, ex:test/term3', 'Prov for term1', 'ex:XYZ/term1'),  # noqa:E501
-        # ('ex:test/term1', 'Begr1', 'de', 'Def für Begr1', 'de', 'für Begr1', None, None, None),  # noqa:E501
         ('ex:test/term2', 'term2', 'en', 'def for term2', 'en', 'AltLbl for term2', 'ex:test/term4', 'Prov for term2', 'ex:XYZ/term2'),  # noqa:E501
         ('ex:test/term3', 'term3', 'en', 'def for term3', 'en', 'AltLbl for term3', 'ex:test/term4', 'Prov for term3', 'ex:XYZ/term3'),  # noqa:E501
         ('ex:test/term4', 'term4', 'en', 'def for term4', 'en', 'AltLbl for term4', None,            'Prov for term4', 'ex:XYZ/term4'),  # noqa:E501
@@ -364,9 +387,7 @@ def test_hierarchy_to_indent_merge(datadir, tmp_path):
     wb.close()
     with pytest.raises(ValueError) as excinfo:
         main_cli(["--hierarchy-to-indent", "--no-warn", str(tmp_path / new_filename)])
-    assert f"Merge conflict for concept {iri} in column" in str(
-        excinfo.value  # noqa: WPS441
-    )
+    assert f"Merge conflict for concept {iri}" in str(excinfo.value)  # noqa: WPS441
 
 
 @pytest.mark.parametrize(