Cathodic current efficiency in the chlorate process

2006 ◽  
Vol 37 (1) ◽  
pp. 181-186 ◽  
Author(s):  
Josefin Wulff ◽  
Ann Cornell
Keyword(s):  
Current Efficiency ◽  
Cathodic Current ◽  
Cathodic Current Efficiency

scholarly journals Electrodeposition of Zn-Fe Alloy from Non-Cyanide Alkaline Sulphate Bath Containing Tartarate

2020 ◽  
Vol 6 (1) ◽  
pp. 180-183 ◽  
Author(s):  
V. Narasimhamurthy ◽  
L.H. Shivashankarappa
Keyword(s):  
Surface Morphology ◽  
Current Efficiency ◽  
Iron Content ◽  
Operating Conditions ◽  
Cathodic Current ◽  
Cyclic Voltammetric ◽  
Cathodic Current Efficiency ◽  
Voltammetric Studies ◽  
Sulphate Bath ◽  
Cyclic Voltammetric Studies

Electrodeposition of Zn-Fe alloy from an alkaline sulphate bath containing tartarate has been carried out. The effect of plating variables on the composition of alloy and on cathodic current efficiency was studied. The cyclic voltammetric studies carried out to know the mutual co-deposition of zinc and iron. Hardness and the surface morphology of the alloy deposits were found to be dependent on the iron content in the alloy. An alloy containing 20% wt. Fe showed smooth, uniform and finer grained deposits. Under the optimum composition and operating conditions, Zn-Fe alloy deposition from alkaline sulphate bath containing tartarate followed anomalous depositing process.

scholarly journals Methods to Determine the Current Efficiency in AC Electrolysis

2020 ◽  
Vol 46 (1) ◽  
pp. 343-352
Author(s):  
S. Yu. Kireev ◽  
Yu. P. Perelygin ◽  
S. N. Kireeva ◽  
M. J. Jaskula
Keyword(s):  
Current Efficiency ◽  
Double Layer ◽  
Pulse Current ◽  
Metal Deposition ◽  
Cathodic Current ◽  
Cathodic Current Efficiency ◽  
Deposition Processes ◽  
Methods Analytical ◽  
Experimental Researches

AbstractThe paper presents several methods (analytical, electromechanical and electronic) for determining the cathodic current efficiency of the metal deposition processes carried out by AC or pulse current. Based on the results of own experimental researches (for indium, cadmium, nickel, tin and zinc), the appropriate equations are given and the distribution of both faradaic and non-faradaic parts of charge (charging of the electrode double layer) is calculated.

The Research about EDTA Plating Solutions of Non-Cyanide Copper Plating

2012 ◽  
Vol 472-475 ◽  
pp. 2795-2800
Author(s):  
Ren Chun Fu ◽  
Zhong Cheng Guo ◽  
Wei Min Zhou ◽  
Zhen Chen
Keyword(s):  
Current Efficiency ◽  
Complexing Agent ◽  
Copper Plating ◽  
Cathodic Current ◽  
Throwing Power ◽  
Cathodic Current Efficiency ◽  
Plating Solution ◽  
Better Than ◽  
Covering Power

Six formulae of plating solution were studyed in the experiment. The first formula was cyanide plating solutions. The others formulae based on the EDTA as primary complexing agent, C6H5O7K3•H2O and KNaC4H4O6•4H2O as auxiliary complexing agent. Bath quality of the six formulae were examined and Compared. The results show that the EDTA system improve the ability of throwing power, covering power, current efficiency and reduce the bath voltage. In some ways, the performance of EDTA system were better than cyanide plating solutions, such as the deep plating ability, dispersing power, cathodic current efficiency.

Dependence of Titanium Deposition upon Its Ionic State in Molten Salt

2004 ◽  
Vol 449-452 ◽  
pp. 453-456 ◽  
Author(s):  
Toshihide Takenaka ◽  
Masahiro Kawakami ◽  
Naoyuki Suda
Keyword(s):  
Current Efficiency ◽  
Molten Salt ◽  
Electrode Reaction ◽  
Disproportionation Reaction ◽  
Cathodic Current ◽  
Ionic State ◽  
Average Valence ◽  
Cathodic Current Efficiency ◽  
Ionic Valence ◽  
Fluoride Addition

The ionic valence of Ti changed with electrorefining process of Ti in a bath equi-molar mixture of NaCl-KCl containing TiCln(n=2 or 3); The average valence was about 2.3 initially, and became about 2.1 after electrolysis. The cathodic current efficiency was getting better with electrolysis. It should be necessary to maintain the average ionic valence lower for efficient electrolysis in the molten salt. The dominant Ti ion and its electrode reaction changed with the addition of NaF-KF in the molten salt; The average valence shifted from about 2 to about 3, and the total amount of Ti in the bath decreased. The result indicates the disproportionation reaction: 3Ti2+= Ti + 2Ti3+is induced by the fluoride addition. The quantity of electricity for Ti deposition changed consequently, and the purity of the Ti deposit was also affected.

scholarly journals The study of Zn–Co alloy coatings electrochemically deposited by pulse current

2012 ◽  
Vol 66 (5) ◽  
pp. 749-757 ◽  
Author(s):  
Jelena Bajat ◽  
Miodrag Maksimovic ◽  
Milorad Tomic ◽  
Miomir Pavlovic
Keyword(s):  
Surface Roughness ◽  
Current Efficiency ◽  
Direct Current ◽  
Current Density ◽  
Pulse Current ◽  
Pulse Plating ◽  
Cathodic Current ◽  
Average Current Density ◽  
Corrosion Stability ◽  
Average Current

The electrochemical deposition by pulse current of Zn-Co alloy coatings on steel was examined, with the aim to find out whether pulse plating could produce alloys that could offer a better corrosion protection. The influence of on-time and the average current density on the cathodic current efficiency, coating morphology, surface roughness and corrosion stability in 3% NaCl was examined. At the same Ton/Toff ratio the current efficiency was insignificantly smaller for deposition at higher average current density. It was shown that, depending on the on-time, pulse plating could produce more homogenous alloy coatings with finer morphology, as compared to deposits obtained by direct current. The surface roughness was the greatest for Zn-Co alloy coatings deposited with direct current, as compared with alloy coatings deposited with pulse current, for both examined average current densities. It was also shown that Zn-Co alloy coatings deposited by pulse current could increase the corrosion stability of Zn-Co alloy coatings on steel. Namely, alloy coatings deposited with pulse current showed higher corrosion stability, as compared with alloy coatings deposited with direct current, for almost all examined cathodic times, Ton. Alloy coatings deposited at higher average current density showed greater corrosion stability as compared with coatings deposited by pulse current at smaller average current density. It was shown that deposits obtained with pulse current and cathodic time of 10 ms had the poorest corrosion stability, for both investigated average deposition current density. Among all investigated alloy coatings the highest corrosion stability was obtained for Zn-Co alloy coatings deposited with pulsed current at higher average current density (jav = 4 A dm-2).

Effect of Saccharin Addition on the Electrodeposition of Nickel from a Watts-Type Electrolyte

2011 ◽  
Vol 189-193 ◽  
pp. 911-914 ◽  
Author(s):  
Yan Wei Li ◽  
Xiao Xi Huang ◽  
Jin Huan Yao ◽  
Xing Shen Deng
Keyword(s):  
Surface Morphology ◽  
Tensile Stress ◽  
Cathodic Polarization ◽  
Cathodic Current ◽  
Nickel Deposition ◽  
Plating Bath ◽  
Nickel Electrodeposition ◽  
Cathodic Current Efficiency ◽  
Electrodeposition Of Nickel ◽  
Type Electrolyte

The influence of saccharin addition on cathodic polarization, cathodic current efficiency, hardness, surface morphology, and internal stress of nickel electrodeposition from a Watts-type plating bath was studied in this work. The results show that the addition of saccharin may enhance the cathodic polarization, modify the surface morphology, increase the hardness, and decrease the tensile stress. In particular, when the concentration of saccharin is 0.4 g/L, the surface of nickel deposition is smoothest. When the concentration of saccharin is 0.05 g/L, the hardness of nickel deposition is highest.

scholarly journals Efficiency definition of the deposition process of electrochromic Ni(OH)2-PVA films formed on a metal substrate from concentrated solutions

2021 ◽  
Vol 6 (12 (114)) ◽  
Author(s):  
Valerii Kotok ◽  
Vadym Kovalenko ◽  
Rovil Nafeev ◽  
Volodymyr Verbitskiy ◽  
Olena Melnyk ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
Current Efficiency ◽  
Nickel Hydroxide ◽  
Deposition Process ◽  
Amorphous Structure ◽  
Cathode Current Density ◽  
Nickel Nitrate ◽  
Cathodic Current ◽  
Smart Windows ◽  
Lack Of Information

Electrochemical devices based on nickel hydroxide electrodes are used in different areas. The main ones are chemical current sources, variable transparency “smart” windows, devices for carrying out electrocatalytic reactions, sensors for determining various substances. In this regard, methods of nickel hydroxide synthesis are of great interest, especially those that allow forming nickel hydroxide directly on the surface of electrodes. One of these methods is electrochemical deposition with cathodic current polarization. The available information on nickel hydroxide synthesis from nickel solutions was considered. It was shown that the available data mainly covered information on dilute solutions from 0.01 to 0.25 mol/L Ni(NO3)2. In addition, no comparison was found in the literature for the efficiency of the cathodic formation of Ni(OH)2 at different concentrations of nickel nitrate. To eliminate the lack of information, the dependence of the current efficiency on the concentration of nickel nitrate in the electrodeposition solution was determined at a constant cathode current density of 0.625 mA/cm2. The resulting dependence decreased nonlinearly with increasing concentration. The nickel hydroxide deposit formed in this case had an X-ray amorphous structure, and it depended little on the Ni(NO3)2 concentration. In addition, the current efficiency reached zero at concentrations of 1.5 mol/L Ni(NO3)2 and higher. However, with polyvinyl alcohol in the solution and at Ni(NO3)2 concentrations of 1.5 and 2 mol/L, electrochemically and electrochromically active Ni(OH)2 films were deposited. The current efficiency calculated indirectly for 1.5 and 2 mol/L Ni(NO3)2 solutions was 3.2 and 2.3 %, respectively. Thus, it was concluded that polyvinyl alcohol affected the mechanism of nickel hydroxide electrodeposition from aqueous solutions of nickel nitrate.

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