bluuebunny/crossref_metadata_2025_split huggingface dataset:
Advancing Low Temperature Molten Sodium Batteries By Interfacial Engineering of Ceramic Electrolytes
Authors: Gross Martha M. , Peretti Amanda , Small Leo J. , Percival Stephen , Rodriguez Mark , Spoerke Erik D. 
Published: May 2020

Molten sodium batteries show remarkable promise as large-scale energy storage systems, but their widespread deployment has been limited by high operating temperatures (~300°C), which impacts their lifetime, cost, and reliability. Lowering the battery operating temperature promises substantial improvements in these areas, but the lower temperature introduces new challenges to the battery chemistry, especially related to the solid state ion-conducting separators used in these batteries. Traditionally, the high temperature operation has been required to not only maintain high Na+-ion conductivity of solid electrolytes, such as β”-Al2O3 or NaSICON, but also to improve the liquid-solid interfacial wetting of molten sodium on the solid electrolyte. We are focused on drastically reducing the operating temperature to near the melting temperature of sodium (97.8oC), which leads to poor interfacial wetting of the molten sodium. Poor wetting and ineffective charge transfer can dominate battery resistances resulting in a cell-limiting interface. Here, we will describe the rational design of engineered coatings to improve wetting of the molten sodium on NaSICON at low temperatures near 100°C, and therefore improve charge transfer across this critical interface. Enhanced mating of the separator-sodium interface by means of engineered coatings is demonstrated to result in lower interfacial resistance and higher battery performance at increased current densities. This strategy promises substantial advances in the operation of molten sodium batteries at low temperatures and opportunities to expand the utility of these batteries to meet emerging grid-scale needs.
Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.
Influence of Ligands on the Cu(I/II) Redox Reaction for Redox Flow Batteries
Authors: Hall Derek M. , Springer Renaldo , Gorski Christopher A. , Lvov Serguei N 
Published: May 2020

For meeting ambitious carbon-free electricity goals, low-cost electrical energy storage solutions are needed. Although redox flow batteries are a promising option to satisfy this need, the cost of these devices must decrease before widespread adoption can take place. As the electrolytes are the most significant expense for MW-scale flow batteries, new chemistries derived from inexpensive metals is one approach that may alleviate this bottleneck towards a carbon-free power grid. Here we use an electrochemical approach by applying a rotating disc electrode (RDE) to quantify how ligand chemistries can favorably manipulate the electrochemical parameters of the Cu(I/II) redox reaction, progressing these chemistries forward as potential low-cost electrolytes for redox flow batteries.
In this research, multiple ligands were used to analyze such impacts on aqueous copper metal complexes by using both a platinum and carbon tipped electrode installed into the RDE. Electrochemical Impedance Spectroscopy (EIS), Linear Sweep Voltammetry (LSV) and Open Circuit Potential (OCP) were the three techniques utilized to analyze the effects of these metal complexes. The experimental data was analyzed using the Butler-Volmer and Nernst equations. As step reactions are mostly unknown for these reactions, LSV and EIS data gave insights into what may be occurring at the electrode interfaces. OCP data quantified how different ligands modified the standard electrode potentials of the Cu(I/II) redox reaction.
Pt Nanoparticle Sensitized PdNi Nanofibers As Highly Sensitive and Selective Hydrogen Gas Sensor
Authors: Ko Jaehyun , Koo Won-Tae , Kim Il-Doo 
Published: May 2020

Detection of different gases in power transformer oil is essential to accurately examine and understand different problems and faults in the transformer system. Especially, during situations like corona discharge and arcing, evolution of hydrogen gas can be hazardous due to its highly flammable and explosive nature. Therefore, development of high-performance gas sensors targeted for hydrogen gas over a wide range of concentrations is very important.
We suggest a facile and effective fabrication method of hydrogen sensing composite material based on palladium and nickel alloy with nanofiber structures originated from electrospinning. PdNi alloy, with further decoration with platinum nanoparticles as catalysts via apo-ferritin templating, shows greatly enhanced sensitivity and response time. Conventionally, Palladium is widely used as hydrogen sensors due to its well-known phase transition to PdHx, α-PdHx at hydrogen concentration below 1%, and β-PdHx at hydrogen concentration above 2%. However, huge volume expansion associated from this transformation limits its lifetime and reduces its long-term performance. In this work, nickel alloying effectively decreases the lattice parameters of the alloy, while increasing the stability during repetitive exposure to high concentration to hydrogen gas. Furthermore, formation of grain boundaries to compensate the lattice contraction induced by nickel alloying, high surface area from its nanofiber structure and gas dissociation and activation properties of platinum nanoparticles improves the sensor’s sensitivity toward hydrogen gas [1]. Nickel in the lattice also acts as pinning points to effectively suppress the grain growth of the alloy during high temperature annealing and reduction processes, which further improves its sensitivity and response time. This facile fabrication and decoration methods allow us to produce a highly sensitive and rapidly responding hydrogen gas sensor with enhanced long-term stability compared to the conventional Pd based hydrogen gas sensors.

Reference

[1] D. H. Kim, ACS
Nano 13, 6071–6082 (2011); doi:10.1021/acsnano.9b02481
Multiplexed Bioanalysis Based on Light-sensitive Electrodes
Authors: Zhao S. , Riedel Marc , Yue Z. , Parak Wolfgang , Lisdat Fred 
Published: May 2020

Introduction
Quantum dots (QDs) have become attractive tools in bioanalysis because of their advantageous optical and electrochemical properties. This relates to applications exploiting fluorescence, electrochemiluminescence or photocurrent generation [1]. For the latter case QDs are immobilized on conductive electrodes. By light excitation charge carriers are formed inside the nanoparticles which can be used for photocurrent generation. Signal chains can be constructed when appropriate donor or acceptor components are present in solution. The special feature of such electrodes is that the response is triggered by illumination of the sensing electrode [1]. In this study, a light-addressable photoelectrochemical sensor was built by coupling QDs with oxidases to detect different enzyme substrates.

Results and Conclusions

At first CdSe/ZnS QDs have been immobilised via a dithiol compound on gold electrodes. Two different enzymes, glucose oxidase (GOD) and sarcosine oxidase (SOD) have been deposited on this QDs-electrode at spatially well resolved places. Here small spots have been achieved by a dropping method. A laser beam is moved over the spots to detect photocurrents. Since oxygen can act as electron acceptor at the illuminated QDs the photocurrent is correlated to the oxygen concentration in solution. By action of the enzymes in the presence of the corresponding substrate a competitive situation for oxygen is created in front of the QD layer and thus, the photocurrent decreases [2, 3]. Since this happens in a concentration dependent way, analysis of the enzyme substrate is feasible.
Furthermore, due to the spatially separated immobilisation of the two enzymes, an independent read-out of the two enzyme reactions is possible. The results indicate good lateral resolution and selectivity of the multi-detection system without any crosstalk between the two sensing regions and also without any response at regions, which have not been modified with an enzyme [4].
After that, the possibility of an imaging of the enzyme spot by photocurrent measurement has been studied. When the laser is moved over the spot of GOD with a constant speed, the size of the spot can be determined from the photocurrent - time curve (with a defined moving speed). The photocurrent correlates to different local enzyme activities. Consequently, an imaging of the enzyme activity distribution on the surface has also been achieved by this method.

References

[1] F. Lisdat, D. Schäfer, A. Kapp, Analytical and Bioanalytical Chemistry 405 (2013) 3739-3752
[2] M. Riedel, et al., Chem. Phys. Chem. 2013, 14, 2338-2342.
[3] J. Tanne et al., Anal. Chem. 2011, 83, 7778-7785.
[4] S. Zhao et al., ACS Applied Materials & Interfaces, 2019, Vol. 11 (24), p. 21830-21839
Electrochemically Stimulated Molecule Releaseassociated with Interfacial pH Changes
Authors: Kadambar Vasantha Krishna , Bellare Madhura , Katz Evgeny , Bollella Paolo , Melman Artem 
Published: May 2020

External signal-stimulated release of (bio)molecules is used in many biotechnological and biomedical applications1. It has been well documented over decades, resulting in vast group of physical and chemical systems functioning differently and reacting to different signals. Among various molecule-releasing systems responding to different activating signals (e.g.; optical, magnetic, chemical, mechanical, temperature change, etc.); electrochemical systems is one of the most important and interesting research fields. Besides systems controlled by electrostatic attraction/repulsion of molecules at polarized electrode surfaces2,3, more sophisticated systems that are able to release only specific molecules are based on molecular and supramolecular systems can be tailored. In the latter case, selected molecules are included in complex structures assembled at electrode surfaces and disassembled upon electrochemical processes. Some of these systems have electrochemically cleavable covalent bonds (e.g., disulfide bonds), which results in the release of the connected molecules upon redox reaction. While the electrochemical cleavage of bonds based on the redox transformations is a very powerful and successful approach in clean model systems, it may be significantly complicated in the presence of other redox species appearing in complex biological media. Thus, more universal approaches to the electrochemically stimulated cleavage of chemical bonds should be investigated. Herein we report a new linker with a hydrolysable phenolic ester bond at basic pH (~8-10) for electrode modification. Basic pH locally produced at the electrode surface upon electrochemical reduction of oxygen resulted in the hydrolytic cleavage of the phenolic ester bond and release of the immobilized fluorescent dye used as a model compound4.
ǂ These authors equally contributed to the work

References:

1. Katz, E., Pingarron, J. M., Mailloux, S., Guz, N., Gamella, M., Melman, G., & Melman, A. Substance release triggered by biomolecular signals in bioelectronic systems.The journal of physical chemistry letters, 2015, 6(8), 1340-1347.
2. Sempionatto, J. R., Gamella, M., Guz, N., Pingarrón, J. M., Pedrosa, V. A., Minko, S., & Katz, E. Electrochemically Stimulated DNA Release from a Polymer‐Brush Modified Electrode. Electroanalysis, 2015, 27(9), 2171-2179.
3. Masi, M., Bollella, P., & Katz, E. Biomolecular Release Stimulated by Electrochemical Signals at a Very Small Potential Applied. 2019, Electroanalysis. Accepted manuscript.
4. Bellare, M.; Kadambar, V. K.; Bollella, P.; Katz, E. and Melman, A; Electrochemically stimulated molecule release associated with interfacial pH changes Commun., 2019, 55, 7856-7859.
Atomically-Dispersed Functional Materials: From Single-Atom Electrocatalysts to Single-Atom Nanozymes
Authors: Du Dan , Lin Yuehe 
Published: May 2020

Nanomaterials with enzyme‐like activities, or nanozymes, have attracted lots of attention recently due to their advantages such as low cost, superior activity, and high stability. The complex structure and composition of nanozymes has led to extensive investigation of their catalytic sites at an atomic scale, and to an in‐depth understanding of the biocatalysis mechanisms.
Single-atom catalysts (SACs) offer the unique feature of maximum atomic utilization, providing a potential pathway to improve the catalytic activity of nanozymes. Recently, we have demonstrated a Fe-N-C single-atom nanozyme (SAN) that exhibits high peroxidase-like activity. The SAN consists of atomically dispersed Fe─Nx moieties hosted by metal–organic frameworks (MOF) derived porous carbon. Due to high single-atom active Fe dispersion and the large surface area of the porous support, the SAN provided a high specific activity which was almost at the same level as natural horseradish peroxidase (HRP). Besides, the Fe-N-C based SAN presented much better storage stability and robustness against harsh environments compared with natural enzymes. The biosensing applications of the SAN and their major challenges will be discussed.

References:

1. L. Jiao, H. Yan, Y. Wu, W. Gu, C. Zhu, D. Du, Y. Lin. When Nanozymes Meet Single-Atom Catalysis. Angew. Chem. Int. Ed. 2019, doi.org/10.1002/ange.201905645
2. C. Zhu, S. Fu, Q. Shi, D. Du, Y. Lin. Single-Atom Electrocatalysts. Angew. Chem. Int. Ed. 2017, 56, 13944-13960.
3. N. Cheng, J. Li, D. Liu, Y. Lin, D. Du. Single-Atom Nanozyme Based on Nanoengineered Fe-N-C Catalyst with Superior Peroxidase-Like Activity for Ultrasensitive Bioassays. Small, 2019, 1901485.
4. X. Niu, Q. Shi, W. Zhu, D. Liu, H. Tian, S. Fu, N. Cheng, S. Li, J. N Smith, D. Du, Y. Lin. Unprecedented peroxidase-mimicking activity of single-atom nanozyme with atomically dispersed Fe-Nx moieties hosted by MOF derived porous carbon. Biosensors & Bioelectronics, 2019, 142, 111495.
5. Y Wu, L Jiao, X Luo, W Xu, X Wei, H Wang, H Yan, W Gu, BZ Xu, D Du, Y. Lin, C. Zhu. Oxidase‐Like Fe‐N‐C Single‐Atom Nanozymes for the Detection of Acetylcholinesterase Activity. Small, 2019, 15, 1903108
6. L Jiao, W Xu, H Yan, Y Wu, C Liu, D Du, Y Lin, C Zhu. Fe-NC Single-Atom Nanozyme for the Intracellular Hydrogen Peroxide Detection. Anal. Chem., 2019, 91, 11994-11999
Tailored Carbon Nanotube-Based Fluorescent Sensors for Cellular Metabolites
Authors: Nißler Robert , Kruss Sebastian 
Published: May 2020

Single-walled carbon nanotubes (SWCNTs) are an emerging building block for nanoscale sensors and labels because of their unique photophysical properties. Semiconducting SWCNTs fluoresce in the tissue transparency near infrared (nIR) window (840 – 1650 nm) and do not bleach. Due to their 1D nature small perturbations in their environment strongly affect their fluorescence. The major challenges in using SWCNTS for sensing is on the one side their purification and on the other side a tailored surface chemistry for molecular recognition and photophysical signal transduction. Cellular metabolites such as first messengers are important biomolecules used by cells to exchange both energy and information but up to day there are many such molecules for which no sensors exist. DNA is a versatile macromolecule to functionalize and solubilize SWCNTs. Furthermore, DNA acts as a conformational quantum yield switch, which makes it a good candidate to impart signal transduction. However, different sensing strategies are known, but general recognition capabilities need to be further explored. Here, we present three different approaches with DNA to tailor SWCNT surface chemistry and detect biologically important metabolites.
Firstly, we tuned the sensitivity of ssDNA/SWCNTs against the neurotransmitter dopamine and different plant polyphenols by changing systematically the DNA sequence. In a more rational approach, we engineered DNA strands conjugated to small peptide sequences. In order to enable a ratio-specific linkage, we determined the amount of bound DNA on the SWCNT surface, which was further observed to play an important role in maintaining colloidal stability of the modified ssDNA/SWCNT conjugates. Finally, aptamer-based approaches were used to combine stable surface modification with target selective binding.
For all these approaches we demonstrated via nIR-fluorescence spectroscopy and nIR-fluorescence microscopy that tailoring these nanosensors resulted in an increased specificity against their targets, ranging from small chemical communication compounds (dopamine, H2O2) to cell wall components and secreted enzymes.
Switchable Dopants on Percolation Networks of 2D Materials for Chemiresistive Sensing Applications in Aqueous Environments
Authors: Kruse Peter 
Published: May 2020

Permanent doping of semiconductors and low-dimensional structures to modulate their electronic properties is a well-established concept. Even in cases where doping of thin films by analytes (e.g. carbon nanotubes by ammonia) is applied in sensors, it is only reversed by physical removal of dopant molecules, e.g. heating. We have introduced the concept of molecular switches as chemical dopants for thin nanocarbon (or other 2D-materials) films. These molecules can be switched between doping and non-doping states in the presence or absence of a particular analyte. They impart selectivity not only due to their change in doping behavior, but also by physically blocking other potential dopants in the analyte solution from interacting with the conductive film. The resulting structures can act as chemiresistive films.
Chemiresistive sensors are a well-established technology for gas-phase sensing applications. They are simple and economical to manufacture, and can operate reagent-free and with low or no maintenance. Unlike electrochemical sensors they do not require reference electrodes. While in principle they can be made compatible with aqueous environments, only a few such examples have been demonstrated. Challenges include the need to prevent electrical shorts through the aqueous medium and the need to keep the sensing voltage low enough to avoid electrochemical reactions at the sensor. We have built a chemiresistive sensing platform for aqueous media. The active sensor element consists of a percolation network of low-dimensional materials particles that form a conducting film, e.g. from carbon nanotubes, pencil trace, exfoliated graphene or MoS2. The first member of that platform was a free chlorine sensor.[1-3] We are currently working to expand the applicability of our platform to other relevant species, in particular anions and cations that are commonly present as pollutants in surface and drinking water.[4] Our sensors can be incorporated into a variety of systems and will also be suitable for online monitoring in remote and resource-poor locations.
[1] L. H. H. Hsu, E. Hoque, P. Kruse, and P. R. Selvaganapathy, A carbon nanotube based resettable sensor for measuring free chlorine in drinking water. Appl. Phys. Lett. 106 (2015) 063102.
[2] E. Hoque, L. H. H. Hsu, A. Aryasomayajula, P. R. Selvaganapathy, and P. Kruse, Pencil-Drawn Chemiresistive Sensor for Free Chlorine in Water. IEEE Sens. Lett. 1 (2017) 4500504.
[3] A. Mohtasebi, A. D. Broomfield, T. Chowdhury, P. R. Selvaganapathy, and P. Kruse, Reagent-Free Quantification of Aqueous Free Chlorine via Electrical Readout of Colorimetrically Functionalized Pencil Lines. ACS Appl. Mater. Interfaces 9 (2017) 20748-20761.
[4] P. Kruse, Review on Water Quality Sensors. J. Phys. D 51 (2018) 203002.

Figure 1
(Invited) Production of Liquid Hydrocarbons from Anaerobic Digester Gas
Authors: Hartvigsen Joseph J. , Elangovan S. , Frost Lyman J. 
Published: May 2020

OxEon Energy, LLC (OxEon) plans to demonstrate production liquid hydrocarbon fuels using both the methane and CO2 generated in the food waste digester operated by the Environmental Products & Technologies Corporation (EPT). The EPT food waste digester in Burley Idaho sells produced biogas into a natural gas pipeline after separating and venting the bio-CO2. This project will convert the bio-methane to synthesis gas (syngas, as CO & H2) using a non-thermal plasma catalyzed autothermal reformer. To achieve high bio-carbon utilization, high temperature solid oxide co-electrolysis (HTCE) system will electrochemically generate additional syngas from the bio-CO2 combined with steam raised by cooling the Fischer Tropsch (FT) reactor. Syngas from the reformed methane and co-electrolyzed CO2, will be converted to liquid fuels using the FT reactor. Each of the technology components have been field tested independently and will be combined for the first time in this project. The project outcome will be an engineering scale demonstration of liquid hydrocarbon bio-fuel production achieving > 50% conversion to liquids of the biogenic carbon in both CH4 & CO2 produced by an anaerobic digester.
Each of the three technology elements of the integrated engineering test incorporates numerous innovations. The plasma reactor is designed to be fuel flexible, sulfur tolerant, and economically scalable to small, distributed bio-gas resources. It is also very efficient using a low power non- thermal plasma. High temperature electrolysis has demonstrated efficiency at the thermodynamic limit as shown by analysis and testing at DOE and NASA laboratories, and is unique in its ability to co-electrolyze steam and CO2 directly to syngas. The HTCE stacks use innovations proven for the NASA Mars 2020 project which required exceptional ruggedness and effective high temperature seals. The FT reactor enables economical fabrication of smaller size synthetic fuel plants designed to match the scale of distributed renewable biomass resources. This is achieved with large diameter standard piping combined with a novel internal thermal management structure.
The status of the technology elements and the planned engineering demonstration will be presented.
This work is supported by the Bioenergy Technologies Office of the US Department of Energy.