THE DEPENDENCE OF CONCENTRATION GRADIENT ON CURRENT DENSITY AT WORKING ELECTRODES

1965 ◽  
Vol 43 (12) ◽  
pp. 3304-3310 ◽  
Author(s):  
R. N. O'Brien ◽  
C. A. Rosenfield ◽  
K. Kinoshita ◽  
W. F. Yakymyshyn ◽  
J. Leja
Keyword(s):  
Current Density ◽  
Concentration Gradient ◽  
Fringe Pattern ◽  
Electrolyte Concentration ◽  
Error Function ◽  
A Cell ◽  
Interferometric Study

An interferometric study of working electrodes in a cell holding less than 1 ml of solution enabled the effects of cell depth, orientation, electrolyte concentration, and temperature on the concentration gradient to be evaluated. The concentration gradient (obtained from the perturbations of a parallel fringe pattern) is an error function of current density, but every factor studied produced deviation from this relationship. The electrodeposition of the following ions has been studied: Cu++, Zn++, Ni++, Ag+, in a wide variety of electrolytes.

Study on Special Morphology Hydroxyapatite Bioactive Coating by Electrochemical Deposition

2013 ◽  
Vol 537 ◽  
pp. 256-260
Author(s):  
Cai Ge Gu ◽  
Qian Gang Fu ◽  
He Jun Li ◽  
Jin Hua Lu ◽  
Lei Lei Zhang
Keyword(s):  
Electrochemical Deposition ◽  
Current Density ◽  
Electrolyte Concentration ◽  
Spherical Particles ◽  
Constant Current ◽  
Constant Current Density ◽  
Depth Direction ◽  
Special Morphology ◽  
Calcium Phosphate Coatings ◽  
Coating Weight

Bioactive calcium phosphate coatings were deposited on carbon/carbon（C/C） composites using electrochemical deposition technique. The effects of electrolyte concentration and constant current density on morphology, structure and composition of the coating were systematically investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transformed infrared (FTIR) spectroscopy. The results show that, the coating weight elevated gradually with the increase of electrolyte concentration, and the morphology of coatings changed from spherical particles to nanolamellar crystals with interlocking structure initially. Then the coating transformed into seaweed-like and nano/micro-sized crystals along the depth direction of the coating. The coatings showed seaweed-like morphology as the deposition current density was less than 20mA. With the less current density, the coating became more homogenous. However, the coating was fiakiness crysal, with needlike crystal stacked upside as the current density reached to 20mA/cm2. The coating weight was improved gradually when the current density increased from 2.5mA/cm2 to 10mA/cm2, then reduced with the increasing current density in the range of 10 to 20mA/cm2.

scholarly journals Study on the effect of electrocatalytic oxidation treatment of 2,4,6-Trinitrophenol wastewater

2018 ◽  
Vol 238 ◽  
pp. 03003
Author(s):  
Yaling Li ◽  
Wenqiang Jiang ◽  
Ruyu Li
Keyword(s):  
Current Density ◽  
Electrocatalytic Oxidation ◽  
Electrolyte Concentration ◽  
Removal Rate ◽  
Pharmaceutical Chemical ◽  
Oxidation Treatment ◽  
Titanium Electrode ◽  
First Order Kinetics ◽  
Oxidation Technology ◽  
Aromatic Nitro

2,4,6-Trinitrophenol is a toxic aromatic nitro-compounds that widely used in pharmaceutical, chemical and pesticide production. Due to its stable structure and poor biodegradability, advanced electrocatalytic oxidation technology was selected to treat simulated wastewater. The goal of the present work is to optimize the electrolysis conditions such as current density, electrolysis pH, and electrolyte concentration. A Pt modified TiO2 electrode was chosen as the anode accompanied with a titanium electrode of the same size as the cathode The results showed that the removal efficiency of 2,4,6-Trinitrophenol was the highest when the current density was 20mA/cm2, electrolyte pH=5, electrolyte concentration was 2 g/L. Under the optimal condition, the removal rate of 2,4,6-Trinitrophenol reached 99.76% after 120 minutes electrolysis. The decay of TNP could also be described by the pseudo-first-order kinetics formula with respect to TNP concentration. Therefore, electrocatalytic oxidation technology might provide an effective method for the degradation of nitroaromatic organic compounds.

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.

Application of the central composite design for condition optimization for semi-aerobic landfill leachate treatment using electrochemical oxidation

2010 ◽  
Vol 61 (5) ◽  
pp. 1257-1266 ◽  
Author(s):  
Soraya Mohajeri ◽  
Hamidi Abdul Aziz ◽  
Mohamed Hasnain Isa ◽  
Mohammad Ali Zahed ◽  
Mohammed J. K. Bashir ◽  
...  
Keyword(s):  
Reaction Time ◽  
Central Composite Design ◽  
Electrochemical Oxidation ◽  
Current Density ◽  
Landfill Leachate ◽  
Electrolyte Concentration ◽  
Process Conditions ◽  
Leachate Treatment ◽  
Condition Optimization ◽  
Central Composite

In the present study, Electrochemical Oxidation was used to remove COD and color from semi-aerobic landfill leachate collected from Pulau Burung Landfill Site (PBLS), Penang, Malaysia. Experiments were conducted in a batch laboratory-scale system in the presence of NaCl as electrolyte and aluminum electrodes. Central composite design (CCD) under Response surface methodology (RSM) was applied to optimize the electrochemical oxidation process conditions using chemical oxygen demand (COD) and color removals as responses, and the electrolyte concentrations, current density and reaction time as control factors. Analysis of variance (ANOVA) showed good coefficient of determination (R2) values of >0.98, thus ensuring satisfactory fitting of the second-order regression model with the experimental data. In un-optimized condition, maximum removals for COD (48.77%) and color (58.21%) were achieved at current density 80 mA/cm2, electrolyte concentration 3,000 mg/L and reaction time 240 min. While after optimization at current density 75 mA/cm2, electrolyte concentration 2,000 mg/L and reaction time 218 min a maximum of 49.33 and 59.24% removals were observed for COD and color respectively.

scholarly journals Study of flow regimes and gas holdup in a different potentials medium in an aerated column

2020 ◽  
Vol 192 ◽  
pp. 02013
Author(s):  
Konstantin Prokhorov ◽  
Alexander Burdonov ◽  
Peter Henning
Keyword(s):  
Aqueous Solutions ◽  
Current Density ◽  
Electrolyte Concentration ◽  
Flow Regimes ◽  
Gas Holdup ◽  
Membrane Electrolysis ◽  
Hydrogen Bubbles ◽  
Solutions Of Electrolytes ◽  
Bubble Sizes ◽  
Electrolyte Ph

A generation of hydrogen and oxygen bubbles by of aqueous solutions of electrolytes was carried out. Two electrolysis modifications was study: electrolysis without a membrane to production of oxygen and hydrogen and membrane electrolysis with separation of catholyte and anolyte. The influence of the model conditions of the experiment such as electrolyte pH, concentration, and current density and the distribution of bubble sizes and gas holdup in the column are discussed. An inverse dependence of the hydrogen bubbles diameter in the catholyte medium on the current density and a direct dependence on the concentration of electrolytes are experimentally investigated. The oxygen bubbles tend to become larger with increasing current density and electrolyte concentration in anolyte medium. In electrolysis without a membrane, bubbles become smaller with increasing current density and decreasing the electrolyte concentration.

scholarly journals Characterising Lithium-Ion Electrolytes via Operando Raman Microspectroscopy

2020 ◽  
Author(s):  
Jack Fawdon ◽  
Johannes Ihli ◽  
Fabio La Mantia ◽  
Mauro Pasta
Keyword(s):  
Thermodynamic Properties ◽  
Concentration Gradient ◽  
Electrolyte Concentration ◽  
Electrochemical Impedance ◽  
Lithium Ion ◽  
Transference Number ◽  
Model System ◽  
Raman Microspectroscopy ◽  
Apparent Diffusion ◽  
Li Ion

<div><div><div><p>Knowledge of electrolyte transport and thermodynamic properties in Li-ion and ”beyond Li-ion” technologies is vital for their continued development and success. Here, we present a method for fully characterising electrolyte systems. By measuring the electrolyte concentration gradient over time via operando Raman microspectroscopy, in tandem with potentiostatic electrochemical impedance spectroscopy, the Fickian ”apparent” diffusion coefficient, transference number, thermodynamic factor, ionic conductivity and resistance of charge-transfer were quantified within a single experimental setup. Using lithium bis(fluorosulfonyl)imide (LiFSI) in tetraglyme (G4) as a model system, our study provides a visualisation of the electrolyte concentration gradient; a method for determining key electrolyte properties, and a necessary technique for correlating intermolecular electrolyte structure with the described transport and thermodynamic properties.</p></div></div></div>

scholarly journals INFLUENCE OF SKIN EFFECT ON THE CALCULATION OF BUSBAR SYSTEMS HAVING RECTANGULAR CROSS SECTION

2021 ◽  
Vol 20 (1) ◽  
pp. 057
Author(s):  
Nebojša Raičević ◽  
Ana Vučković ◽  
Mirjana Perić ◽  
Slavoljub Aleksić
Keyword(s):  
Electromagnetic Field ◽  
Cross Section ◽  
Current Density ◽  
Proximity Effect ◽  
Skin Effect ◽  
Rectangular Cross Section ◽  
Error Function ◽  
Current Density Distribution ◽  
Accurate Solution ◽  
Flow Through

One method for the calculation of current density distribution in a finite number of long parallel conductors, having rectangular cross section, is proposed in this paper. Numerical results aim to highlight the importance of the skin effect, which can be combined with the proximity effect. The method of superposition of these two effects was applied to the calculation of the electromagnetic field in electric power busbars systems. It has been shown that the skin effect has a much greater impact, especially when the conductors are thin and strong electric currents flow through them, so special attention is paid to its calculation. For numerical solution the integral equations are used. The function of current density is approximated by the finite functional series. This way leads to a very accurate solution with only two terms. Differential evolution method is applied for minimization of error function. To demonstrate the application of the proposed approach, numerical values for busbars are presented and compared with values obtained by using the finite elements method.

An advanced and highly efficient Ce assisted NiFe-LDH electrocatalyst for overall water splitting

2020 ◽  
Vol 4 (1) ◽  
pp. 312-323 ◽  
Author(s):  
Harsharaj S. Jadhav ◽  
Animesh Roy ◽  
Bezawit Z. Desalegan ◽  
Jeong Gil Seo
Keyword(s):  
Water Splitting ◽  
Current Density ◽  
Room Temperature ◽  
Cell Voltage ◽  
Highly Efficient ◽  
Overall Water Splitting ◽  
A Cell ◽  
A Current

A room-temperature synthesized NiFeCe2 electrocatalyst delivered a current density of 10 mA cm−2 at a cell voltage of 1.59 V when used as the electrolyzer.

Dye Wastewater Treatment by Means of Electrochemistry in Diaphragm Electrolyzer

2012 ◽  
Vol 178-181 ◽  
pp. 557-561
Author(s):  
Jun Sheng Hu ◽  
Jia Li Dong ◽  
Ying Wang ◽  
Xue Dong Ren
Keyword(s):  
Current Density ◽  
Electrolyte Concentration ◽  
Ph Value ◽  
Aeration Rate ◽  
Alkaline Condition ◽  
Porous Graphite ◽  
Initial Ph ◽  
Cathode Area ◽  
Simulated Wastewater ◽  
Diaphragm Cell

In diaphragm cell, by using the porous graphite as anode, ACF as the cathode, acid scarlet 3R as simulated wastewater, the experiment researched into the effect of current density, electrolyte concentration, aeration rate and the initial pH value on the color removal of wastewater. The results show that the decolourization efficiency increased gradually when the applied current density increases, but the trend will slow down when current density exceeds a certain value. The decolourization efficiency is proved to be first increases then decreases with increased electrolyte concentration and aeration rate, both excessively high and low electrolyte concentration are unfavorable to the removal of wastewater, however the aeration effect is smaller. The effect on decolorization is greater in acid condition than in alkaline condition. As the diaphragm, electrolyzer resistance increase, its average decolourization efficiency is lower than without diaphragm cell, and the decolourization efficiency of cathode area is significantly higher than the anode area.

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