Query: electrochemical copper oxide films effect of bath PH

Candidate papers:

abstract: PREPARATION AND CHARACTERIZATION OF PROPERTIES OF ELECTRODEPOSITED COPPER OXIDE FILMS Publication No. ______ LONGCHENG WANG, PhD. The University of Texas at Arlington, 2006 Supervising Professor: MENG TAO Copper oxides, including cuprous oxide and cupric oxide, are prepared by electrochemical deposition. The structural, optical and electrical properties of as deposited copper oxides are evaluated, based on which cuprous oxide is selected as a promising material for photovoltaic applications. Electrodeposited cuprous oxide is a p type semiconductor with a direct band gap of 2.06 eV. The mechanism of how pH affects the structural and electrical properties of electro deposited cuprous oxide films is studied. In the pH range of 7.5 to 12.0, there are three different preferred crystal orientations: (100) (110) and (111) With different orientations, cuprous oxide shows different surface morphology and iv grain size. Bath pH effect on structural properties is explained by its effect on the growth rate of different crystallographic planes with different Cu/O ratios. Capacitance voltage measurements are performed to study electrical properties of differently oriented cuprous oxide films. The results show that the flat band potential shifts negatively as the bath pH increases. Electrodeposited cupric oxide is a p type cupric oxide with an indirect band gap of 1.32 eV. Different cleaning methods are used to clean the substrate surface for electrodeposition of cupric oxide. Electrochemical etching is proven to be an effective method for Cu substrate cleaning in cupric oxide deposition. In particular, in situ electrochemical etching is developed, which prevents the cleaned substrate from exposure to air. Current voltage characterization shows that cupric oxide deposited on electrochemically etched Cu substrates has favorable electrical properties and better rectification behavior. Cuprous oxide is selected for the fabrication of p n homo junction because it has better crystallinity, bigger grains, better control over crystal quality and a direct band gap. Based on the model that bath pH can control the stoichiometry and native point defects in electrodeposited cuprous oxide films, both p type and n type cuprous oxides are successfully deposited at different bath pH values. For samples deposited at pH below 7.5, cuprous oxides are n type semiconductors, while at bath pH above 9.0, cuprous oxides are p type semiconductors. Furthermore, a two step deposition process is developed to fabricate a p n homo junction in cuprous oxide. Current voltage measurements show a typical rectification behavior of a p n junction for these samples,
author_names: Longcheng Wang
title: Preparation and characterization of properties of electrodeposited copper oxide films
year: 2006

abstract: Abstract Copper (I) oxide (Cu 2 O) films were cathodically electrodeposited on Sn doped indium oxide substrates. The influence of electrodeposition bath pH on grain orientation and crystallite shape was carefully re examined using X ray diffraction and scanning electron microscopy. In addition to the (100) and (111) preferred orientations identified in two previous sets of studies, as the bath pH was varied in the present study from 7.5 to 12, a third preferred orientation, (110) was identified in a narrow pH range, 9.4 to 9.9. A remarkable shift in the flat band potential (spanning 500 mV) was measured in a non aqueous electrolyte medium for the various Cu 2 O samples obtained from baths of varying pH.
author_names: Li Chen Wang

Norma R de Tacconi

C Ramannair Chenthamarakshan

Krishnan Rajeshwar

Meng Tao
title: Electrodeposited copper oxide films: Effect of bath pH on grain orientation and orientation dependent interfacial behavior
year: 2007

abstract: Cuprous oxide (Cu 2 O) thin films have been successfully electrodeposited onto indium tin oxide coated glass substrates from copper acetate solution and characterized by x ray diffraction analysis, scanning electron microscopy, ultraviolet visible (UV Vis) spectroscopy, and photoelectrochemical (PEC) and electrical Hall effect measurements. The effect of the solution pH on the structural, morphological, optical, PEC, and electrical properties of the deposited Cu 2 O thin films was investigated. The x ray diffraction results indicated that the prepared Cu 2 O films exhibited good crystallinity with pure cubic structure, while the crystallite size increased with increasing solution pH. The preferential orientation of the deposited films also changed with the pH value. When the solution pH was changed, the surface morphology changed from spherical to pyramidal shape with increasing grain size. The optical characteristics of the Cu 2 O thin films were not significantly affected by changing the solution pH value. PEC measurements revealed that Cu 2 O thin films prepared at pH 6.2 exhibited n type conductivity, while those obtained at pH 11 showed p type conductivity. These results were confirmed by Hall effect measurements. The obtained Cu 2 O thin films would be promising semiconductor materials for use in various applications such as PEC cells and photovoltaic solar cells.
author_names: Hassiba Rahal

Rafiaa Kihal

Abed Mohamed Affoune

Samia Rahal
title: Effect of Solution pH on Properties of Cuprous Oxide Thin Films Prepared by Electrodeposition from a New Bath
venue: Journal of Electronic Materials
year: 2020

abstract: S.BOUDINAR N.BENBRAHIM, K.SEGUENI, A.KADRI Laboratoire de Physique et Chimie des Materiaux (LPCM) Universite Mouloud MAMMERI de Tizi Ouzou, BP 17, RP Tizi Ouzou 15000, Algerie Corresponding author: boudinarphy@yahoo.fr ABSTRACT In this work, the electrodeposition of bismuth oxide from alkaline bath onto a copper substrate was studied. In order to obtain bismuth oxide with a desired crystallographic structure, the effect of annealing temperature on the morphological and structural proprieties of Bi 2 O 3 was investigated. Cyclic voltammetry and chroampermmety methods were used to the electrochemical characterization formation of Bi thin layers. The morphological analysis with the scanning electron microscopy (SEM) shows a different surface morphology according to the experimental condition. The X rays diffraction analysis (XRD) reveals the presence a several Bi 2 O 3 phases according to annealing temperature, which also confirmed by Raman spectroscopy. Key words: Bismuth oxide, Electrodeposition, SEM, XRD, Raman spectroscopy.
author_names: Salem Boudinar
title: Electrochemical synthesis and characterization of Bismuth oxide thin films from alkaline bath: Effect of annealing temperature
year: 2018

abstract: Abstract. The semiconducting properties of anodic passive films formed potentiostatically on polycrystalline copper in aqueous borax solutions were studied using electrochemical impedance spectroscopy, photocurrent spectroscopy and ellipsometric measurements. The semiconducting nature of the cuprous passive layer was analysed as a function of pH (9.2>pH>7.4) electrode potential and with the addition of 3.5 mM Na2CO3 and 8 mM Na2SO4. The different growth conditions change the compactness and the defect or excess of cations accumulated in the compact inner cuprous layer, leading to different semiconducting properties.
author_names: Jorge O Zerbino

Liliana Mabel Gassa
title: Electrochemical impedance spectroscopy study of cuprous oxide films formed on copper: effect of pH and sulfate and carbonate ions
year: 2003

abstract: Abstract The formation of sulfide and oxide films on copper has been studied in sulfide solutions containing chloride and buffered to pH 9 with borate over the temperature range 20 degC to 80 degC. The primary goal was to investigate the susceptibility of copper to pitting corrosion over a range of temperatures expected in a deep geological repository. Films were formed electrochemically and characterized using scanning electron microscopy (SEM) energy dispersive X ray and Raman spectroscopy and X ray diffractometry (XRD) Chalcocite (Cu2S) formation was observed to occur under partially transport controlled conditions in the potential range 0.9 V to 0.3 V vs SCE. At less negative potentials 0.3 V vs SCE) a transition from active dissolution to partial passivation by a copper oxide film was observed. Temperature had only a minor effect on the formation of the sulfide film, but the onset of active dissolution and oxide film formation shifted to lower potentials as the temperature increased.
author_names: M Guo

Christina Lilja

Vahid Dehnavi

Mehran Behazin

J J Noel

David W Shoesmith
title: The anodic formation of sulfide and oxide films on copper in borate buffered aqueous chloride solutions containing sulfide
year: 2020

abstract: A simple two step approach has been employed to synthesize a cobalt nickel copper ternary metal oxide, involving electrochemical precipitation/deposition followed by calcination. The ternary metal hydroxide gets precipitated/deposited from a nitrate bath at the cathode in the catholyte chamber of a two compartment diaphragm cell at room temperature having a pH 3. The microstructure of the ternary hydroxides was modified in situ by two different surfactants such as cetyltrimethylammonium bromide and dodecyltrimethylammonium bromide in the bath aiming for enhanced storage performance in the electrochemical devices. The effect of the surfactant produces a transition from microspheres to nanosheets, and the effect of micelle concentration produces nanospheres at a higher ion concentration. The ternary hydroxides were calcined at 300 degC to obtain the desired ternary mixed oxide materials as the electrode for hybrid supercapacitors. X ray diffraction analysis confirmed the formation of the ternary metal oxide product. The scanning electron microscopy images associated with energy dispersive analysis suggest the formation of a nanostructured porous composite. Ternary metal oxide in the absence and presence of a surfactant served as the cathode and activated carbon served as the anode for supercapacitor application. DTAB added metal oxide showed 95.1% capacitance retention after 1000 cycles, achieving 188 F/g at a current density of 0.1 A/g, and thereafter stable until 5000 cycles, inferring that more transition metals in the oxide along with suitable surfactants at an appropriate micellar concentration may be better for redox reactions and achieving higher electrical conductivity and smaller charge transfer resistance. The role of various metal cations and surfactants as additives in the electrolytic bath has been discussed.
author_names: Avijit Biswal

Prasanna Kumar Panda

Achyuta N Acharya

Subhashree Mohapatra

Nibedita Swain

Bankim Chandra Tripathy

Zhong-Tao Jiang

Manickam Minakshi Sundaram
title: Role of Additives in Electrochemical Deposition of Ternary Metal Oxide Microspheres for Supercapacitor Applications
venue: ACS omega
year: 2020

abstract: Well defined cuprous oxides (Cu2O) with different morphologies were successfully deposited on fluorine doped tin oxide (FTO) covered glass substrates by potentiostatic deposition. The effect of the pH values on the crystal morphologies of Cu2O was studied. The as prepared products were characterized by means of X ray diffraction (XRD) scanning electron microscopy (SEM) linear sweep voltammetry (LSV) electrochemical impedance spectroscopy (EIS) and UV visible spectroscopy. The typical XRD patterns revealed that all Cu2O thin films were pure Cu2O phase. Different crystal morphologies of Cu2O could be obtained by varying pH. The Cu2O thin film was composed of a large number of star like shape grains with the pH of 4.8. With a further increase of the pH, the Cu2O film showed the uniform dendrite morphology. LSV uncovered that ER (reduction potential of Cu2+ to Cu+ increased with the pH value enlargement. According to the EIS, diffusion coefficient of Cu2+ ion was reduced with the increase of the pH. The UV vis absorption spectra revealed that the broad absorption peaks were from 300 to 500 nm and the evaluated band gap of the films was tunable in the range of 2.02 2.67 eV, with the variation of the pH values. According to the experiment and relevant literatures, the probable electrodeposition mechanism of the Cu2O was discussed.
author_names: Guangli Li

Yaohan Huang

Qingfei Fan

Meili Zhang

Qiuming Lan

Xi-mei Fan

Zuowan Zhou

Chaoliang Zhang
title: Effects of bath pH on structural and electrochemical performance of Cu2O
venue: Ionics
year: 2016

abstract: Environmental conditions and health protection worldwide, is a search engine solutions for the surface finishing industry, in the sense use bath solutions, which do not contain toxic substances, and difficult to treat waters waste. Here are the results from the replacement of copper cyanide by copper sulphate in the composition of an electroless brass plating bath; the electroless brass plating process can be applied directly on Zamak alloys, also on low carbon steels and aluminium. The morphological and brass film colour characteristics were evaluated by scanning electron microscopy, optical microscopy, colour parameters L* a* b* with a spectrophotometer and electrochemical techniques, depending on the molar concentration of copper sulphate. This bath was prepared based on a bath of electroless brass patented in Mexico, the composition of this bath using zinc oxide as a source of Zn ions, a suitable complexing agent and a stabilizer, with an alkaline pH and a temperature of 75 deg C. The results indicate that we can control the colour of brass plating with Cu/Zn ratio.
author_names: Gladis P Mendoza-Aragon

Roal Torres-Sanchez

Adan Borunda-Terrazas

Alfredo Aguilar

Carlos Dominguez-Rios
title: EFFECT OF REPLACING COPPER CYANIDE FOR COPPER SULPHATE IN A BRASS ELECTROLESS BATH
year: 2016

abstract: The selective dissolution of thin copper oxide films grown on copper in semi aqueous formulations containing dimethyl sulfoxide (DMSO) ammonium fluoride (NH"4F) and water was studied. Optimization of the formulations was carried out by systematic evaluation of the effect of solvent content and pH on the removal rates of copper oxide films and selectivity towards copper and carbon doped oxide (CDO) low k dielectric film. Copper oxide removal rate of ~180A/min with a selectivity of ~130:1 towards copper and ~20:1 selectivity towards CDO was obtained in a formulation containing 29% DMSO, 1% NH"4F and 70% H"2O at pH 4. Electrochemical impedance spectroscopy studies were performed on this system and the data were analyzed to characterize the copper oxide/electrolyte interface with the ultimate objective of developing an end point detection technique for copper oxide removal.
author_names: N Venkataraman

Srinivasa R Raghavan
title: Dissolution and electrochemical impedance spectroscopy studies of thin copper oxide films on copper in semi aqueous fluoride solutions
year: 2010