scholarly journals Electrochemical method of obtaining copper (II) oxide powders in alkaline electrolyte

2021 ◽  
Vol 2131 (4) ◽  
pp. 042021
Author(s):  
V Demyan ◽  
V Mikhailenko ◽  
I Zhukova
Keyword(s):  
Mass Loss ◽  
Current Density ◽  
Electrochemical Method ◽  
Alkaline Electrolyte ◽  
Copper Oxidation ◽  
Copper Electrodes ◽  
Oxide Powders ◽  
Copper Compounds ◽  
Highly Dispersed ◽  
Naoh Solution

Abstract Within the framework of these studies, an electrochemical method for the synthesis of highly dispersed powders of copper compounds in aqueous solutions of alkalis is presented. The factors influencing the rate of production of nanoscale copper (II) oxide particles are determined. It is shown that during the anodic oxidation of copper by direct current, the speed of highly dispersed powders formation depends on current density, the nature of alkali cation, and the concentration of electrolyte solution. The mass loss of copper electrodes in NaOH solution is higher than in solutions of potassium hydroxide and lithium hydroxide by 10% and 12%, respectively. This experiment suggests that the studied alkalis act similarly on the anodic behavior of copper and the nature of cation does not significantly affect the speed of anodes destruction. The change in the concentration of alkali solution practically does not affect the mass loss of copper electrodes. The speed of copper oxidation remains almost constant over time, but noticeable weight loss and, accordingly, the speed of copper dissolution is achieved within 15 minutes. The speed of copper oxidation does not depend on current density. It is determined by the amount of electricity that has passed. The current density of 1 A/cm2 can be considered optimal.

Elemental mass loss in silicate minerals during x-ray analysis

1990 ◽  
Vol 48 (4) ◽  
pp. 804-805
Author(s):  
P.E. Champness ◽  
R.W. Devenish
Keyword(s):  
Mass Loss ◽  
Current Density ◽  
Damage Mechanism ◽  
Beam Current ◽  
Single Chain ◽  
Plagioclase Feldspar ◽  
X Ray ◽  
Alkali Ions ◽  
Structural Order ◽  
Sheet Silicate

It has long been recognised that silicates can suffer extensive beam damage in electron-beam instruments. The predominant damage mechanism is radiolysis. For instance, damage in quartz, SiO2, results in loss of structural order without mass loss whereas feldspars (framework silicates containing Ca, Na, K) suffer loss of structural order with accompanying mass loss. In the latter case, the alkali ions, particularly Na, are found to migrate away from the area of the beam. The aim of the present study was to investigate the loss of various elements from the common silicate structures during electron irradiation at 100 kV over a range of current densities of 104 - 109 A m−2. (The current density is defined in terms of 50% of total current in the FWHM probe). The silicates so far ivestigated are:- olivine [(Mg, Fe)SiO4], a structure that has isolated Si-O tetrahedra, garnet [(Mg, Ca, Fe)3Al2Si3AO12 another silicate with isolated tetrahedra, pyroxene [-Ca(Mg, Fe)Si2O6 a single-chain silicate; mica [margarite, -Ca2Al4Si4Al4O2O(OH)4], a sheet silicate, and plagioclase feldspar [-NaCaAl3Si5O16]. Ion- thinned samples of each mineral were examined in a VG Microscopes UHV HB501 field- emission STEM. The beam current used was typically - 0.5 nA and the current density was varied by defocussing the electron probe. Energy-dispersive X-ray spectra were collected every 10 seconds for a total of 200 seconds using a Link Systems windowless detector. The thickness of the samples in the area of analysis was normally 50-150 nm.

scholarly journals An electrochemical method to investigate the effects of compound composition on gold dissolution in thiosulfate solution

2020 ◽  
Vol 9 (1) ◽  
pp. 496-502 ◽  
Author(s):  
Zhaohui Zhang ◽  
Bailong Liu ◽  
Mei Wu ◽  
Longxin Sun
Keyword(s):  
Dissolution Rate ◽  
Current Density ◽  
Polarization Resistance ◽  
Electrochemical Method ◽  
Corrosion Current Density ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
Gold Dissolution ◽  
Tafel Polarization ◽  
Edta Solution

AbstractThe electrochemical behavior of gold dissolution in the Cu2+–NH3–S2O32−–EDTA solution has been investigated in detail by deriving and analyzing the Tafel polarization curve, as this method is currently widely implemented for the electrode corrosion analysis. The dissolution rate of gold in Cu2+–NH3–S2O32−–EDTA solution was determined based on the Tafel polarization curves, and the effects of various compound compositions in a Cu2+–NH3–S2O32−–EDTA mixture on the corrosion potential and corrosion current density were analyzed. The results showed that the corrosion potential and polarization resistance decreased, whereas the corrosion current density increased for certain concentrations of S2O32−–NH3–Cu2+ and EDTA, indicating that the dissolution rate of gold had changed. The reason for promoting the dissolution of gold is also discussed.

Preparation of TiO2 (Au) Nanotubes by Hydrothermal Method for Photocatalytic Reduction of Cd2+ Ions

2014 ◽  
Vol 609-610 ◽  
pp. 375-381
Author(s):  
Chun Xiao Feng ◽  
Guang Qing Xu ◽  
Jun Lv ◽  
Zhi Xiang Zheng ◽  
Yu Cheng Wu
Keyword(s):  
Hydrothermal Method ◽  
Au Nanoparticles ◽  
Reduction Method ◽  
Photocatalytic Reduction ◽  
Photocatalytic Properties ◽  
Absorption Intensity ◽  
Reducing Ability ◽  
Highly Dispersed ◽  
Naoh Solution ◽  
Hydrothermal Reduction

Highly dispersed TiO2 nanotubes (TiO2-NTs) were synthesized via the reaction of anatase TiO2 powder with NaOH solution. Au nanoparticles of about 5 nm were deposited on the surface of TiO2-NTs with hydrothermal reduction method. The prepared nanocomposites were well characterized with TEM and XRD. Their photocatalytic properties and reducing ability were investigated by UV-Vis absorption and photocatalytic reduction of Cd2+ ions with different amount of TiO2-NTs and TiO2-NTs (Au) varying from 0.1g to 0.001g. The results from absorption patterns and AAS showed that the absorption intensity of TiO2-NTs (Au) was higher compared with that of TiO2-NTs. Moreover, the concentration of remanent Cd2+ (0.48mg/L) using TiO2-NTs (Au) was lower than that of Cd2+ (0.65mg/L) using TiO2-NTs.

Electrochemical Synthesis and Photocatalytic Activity of Differently Shaped CuOx Particles

2017 ◽  
Vol 13 ◽  
pp. 330-333
Author(s):  
Anna Ulyankina ◽  
Igor Leontyev ◽  
Nina Smirnova
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Electrochemical Method ◽  
Spherical Particles ◽  
Photocatalytic Efficiency ◽  
X Ray Diffraction ◽  
X Ray ◽  
Polyhedral Particles ◽  
Copper Electrodes ◽  
Scanning Electron

CuOx powders with diff erently shaped particles were firstly prepared via an electrochemical method by oxidation and dispersion of copper electrodes in an electrolyte solution under pulse alternating current (PAC). By means of X-ray diffraction (XRD) and scanning electron microscopy (SEM) the current density is found to have an influence on the morphology and composition of CuOx particles. Photocatalytic efficiency of CuOx towards methyl orange (MO) degradation under visible light was investigated. The prepared polyhedral particles show the best photocatalytic activity of 81 % towards MO comparing to octahedral and spherical particles with 70 and 61 %, respectively.

Conductive bimetal organic framework nanorods decorated with highly dispersed Co3O4 nanoparticles as bi-functional electrocatalyst

2021 ◽  
Author(s):  
Yaxin Duan ◽  
Haitao Liu ◽  
Huabing Zhang ◽  
Shaojie Ke ◽  
Shuaize Wang ◽  
...  
Keyword(s):  
Electrocatalytic Activity ◽  
Electronic Conductivity ◽  
Reduction Reaction ◽  
Alkaline Electrolyte ◽  
Co3o4 Nanoparticles ◽  
Cobalt Ions ◽  
Design And Synthesis ◽  
Half Wave ◽  
Highly Dispersed ◽  
Organic Framework

Abstract The poor electronic conductivity and low intrinsic electrocatalytic activity of metal organic frameworks (MOFs) greatly limit their direct application in electrocatalytic reactions. Herein, we report a conductive two-dimensional π–d conjugated Ni and Co bimetal organic framework (MOF)——NiCo-(2,3,6,7,10,11-hexaiminotriphenylene) (NiCo-HITP) nanorods decorated with highly dispersed Co3O4 nanoparticles (NPs) as a promising bi-functional electrocatalyst towards oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) through an effective and facile strategy by modifying the rod-shaped Ni3(HITP)2 crystals using cobalt ions. The triggered electrocatalytic activity of the resulting MOF-based materials was achieved by increasing the electrical conductivity (7.23 S cm-1) originated from Ni3(HITP)2 substrate and also by creating the cooperative catalysis sites of Co-Nx and Co3O4 NPs. Optimized syntheses show a promising ORR activity with a high half-wave potential (0.77 V) and also a significantly improved OER activity compared with pure Ni3(HITP)2 in alkaline electrolyte. Furthermore, a rechargeable Zn–air battery using the as-prepared material as air-cathode also shows a high power density (143.1 mW cm-2) –even comparable to a commercial Pt/C-RuO2-based battery. This methodology offers a new prospect in the design and synthesis of non-carbonized MOF bi-functional electrocatalysts for efficient catalysis towards ORR and OER.

The Application and Research of Electrochemical Method Treating Acid Red 3R Simulation Wastewater by Response Surface Method

2013 ◽  
Vol 295-298 ◽  
pp. 1258-1262
Author(s):  
Jun Sheng Hu ◽  
Lei Guan ◽  
Jia Li Dong ◽  
Ying Wang ◽  
Ying Yong Duan
Keyword(s):  
Response Surface ◽  
Electrochemical Oxidation ◽  
Current Density ◽  
Electrochemical Method ◽  
Electrolyte Concentration ◽  
Ph Value ◽  
Removal Rate ◽  
Oxidation Method ◽  
Surface Method ◽  
Optimal Value

Using electrochemical oxidation method treats the acid red 3R simulation wastewater, investigates the influence of current density, electrolyte concentration, pH-value and aeration and their interaction on the removal rate of chroma. Through the design of Box-Benhnken Design(BBD) and the response surface analysis, the influence sequence of all variables is current density > aeration > electrolyte concentration > pH-value, the influence sequence of all interaction is electrolyte concentration-aeration > current density-aeration ,electrolyte concentration-pH value > current density-pH value > pH value-aeration > current density-electrolyte concentration. Ultimately, the optimal value is 98.4915% under the condition of current density of 6.51mA/cm2,electrolyte concentration of 0.04mol/L,pH-value of 4.17 and aeration of 0.24m3/h.

MOF-derived hierarchical 3D bi-doped CoP nanoflower eletrocatalyst for hydrogen evolution reaction in both acidic and alkaline media

2020 ◽  
Vol 56 (56) ◽  
pp. 7702-7705 ◽  
Author(s):  
Lei Guo ◽  
Xue Bai ◽  
Hui Xue ◽  
Jing Sun ◽  
Tianshan Song ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Current Density ◽  
Alkaline Media ◽  
Alkaline Electrolyte ◽  
Acidic Electrolyte ◽  
Acidic And Alkaline Media ◽  
A Current

A 3D hierarchical Bi-doped CoP nanoflowers electrocatalyst is developed based on a MOF self-sacrifice strategy. The 3% Bi/CoP catalyst delivers a current density of 10 mA cm−2 at low overpotentials of 122 mV in alkaline electrolyte and 150 mV in acidic electrolyte.

The Preparation of Size-Controlled Antimony Nanoparticles by Electrochemical Method

2013 ◽  
Vol 562-565 ◽  
pp. 716-720
Author(s):  
Jian Lin Xu ◽  
Jia Wang ◽  
Li Hui Zhang ◽  
Lei Niu ◽  
Jian Bin Zhang ◽  
...  
Keyword(s):  
Particle Size ◽  
Current Density ◽  
Electrochemical Method ◽  
Infrared Absorption Spectrum ◽  
Average Diameter ◽  
Electrolysis Time ◽  
Electrochemical Technology ◽  
Transmission Electron ◽  
Means Of Transmission ◽  
Size Controlled

This paper prepared some antimony nanoparticles with different particle size by electrochemical method. A method of preparing size-controlled antimony nanoparticles was established in the hydrochloric acid solution, which alkyphenol ethoxylates emulsifier was used as surface dispersants by electrochemical technology based on the optimization of the preparation technology. Those obtained antimony nanoparticles was characterized and analyzed by means of transmission electron microscopy (TEM), Fourier transform infrared absorption spectrum (FT-IR), X-ray diffraction (XRD). The experiment results show that alkyphenol ethoxylates emulsifier can effectively coat on the surface of antimony nanoparticles, current density and electrolysis time have an important influence on the particle size of those obtained antimony nanoparticles. When the current density is 25mA/cm2 and electrolysis time is 30minutes, spherical antimony nanoparticles with an average diameter of 12nm and good dispersion can be prepared.

Effects of Current Density on the Formation of Anodic Oxide Films on AZ91

2006 ◽  
Vol 510-511 ◽  
pp. 166-169
Author(s):  
Seong Jong Kim ◽  
Jeong Il Kim
Keyword(s):  
Corrosion Resistance ◽  
Current Density ◽  
Anodic Polarization ◽  
Oxide Films ◽  
Anodic Oxide ◽  
Anodic Polarization Curve ◽  
Al Alloy ◽  
Anodic Oxide Films ◽  
Active Metal ◽  
Naoh Solution

Magnesium must be surface treated to prevent corrosion, since it is a very active metal electrochemically. On anodizing, a compact film several tens of micrometers thick forms on magnesium, which imparts good corrosion resistance. The Mg-Al alloy (AZ91) was anodized in 1 M NaOH solution. The surface morphology of the anodized films was observed using scanning electron microscopy (SEM), energy-dispersive x-ray (EDX), and electrochemical methods. The effects of current density on the formation of anodic oxide films for a Mg-Al alloy in 1 M NaOH were investigated. In the anodic polarization curve, the reference corrosion potentials were far greater at 4-9 mA/cm2 than at 1 mA/cm2. The film that formed at 1 mA/cm2 was thin, suggesting that parts of the film had been dissolved or destroyed during the anodic polarization test. Corrosion resistance differed owing to concentric differences in current flow. Thick anodic oxide films were formed at higher applied currents.

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