Journal ArticleDOI
The electrochemical study of a chromium plating bath. II. Chromium metal and surface film formation
Jiang Lin-Cai,Derek Pletcher +1 more
TLDR
In this paper, the authors investigated the mechanism of deposition of metallic chromium and the role of surface films in this process and confirmed that chromium deposition occurs at potentials negative to −1.6 V versus Hg/Hg2SO4 and under galvanostatic or potentiostatic conditions, the current efficiency is 30-45%.Abstract:
The investigation of the electrode reactions occurring at metal and vitreous carbon cathodes in the standard chromium electroplating solution, 200 g dm−3 CrO3 and 2 g dm−3 H2SO4, has been continued and this paper considers the mechanism of deposition of metallic chromium and the role of surface films in this process. It is confirmed that chromium deposition occurs at potentials negative to −1.6 V versus Hg/Hg2SO4 and under galvanostatic or potentiostatic conditions, the current efficiency is 30–45%. Moreover at a vitreous carbon electrode, potential step experiments lead to risingI-t transients characteristic of instantaneous nucleation and three dimensional phase growth. At potentials just prior to metal deposition the potential sweep and step experiments show clear evidence for the formation of a strongly passivating film (this may be in addition to an existing less passivating layer). The important of the film varies with H2SO4 concentration and at intermediate concentrations, potential step experiments lead to unusual oscillatingI-t transients.read more
Citations
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Journal ArticleDOI
Electrochemical Reaction Dynamics - A Review
TL;DR: In this paper, the status of research on the dynamics of electrochemical reactions is reviewed, including the electrodissolution of metals, cathodic deposition, and electrocatalytic reactions.
Journal ArticleDOI
Removal of chromium from aqueous solutions by treatment with porous carbon electrodes: electrochemical principles
D. Golub,Yoram Oren +1 more
TL;DR: In this article, the possibility of removing hexavalent chromium from waste water by electrochemical treatment using a graphite felt electrode and synthetic electrolytes is investigated, and it is suggested that the process proceeds in two steps: electrochemical reduction of the hexavion chromium to chromic ion followed by the formation of an insoluble chromic hydroxide in an electrochemically generated high pH environment.
Journal ArticleDOI
Current oscillations in the reduction or oxidation of some anions involving convection mass transfer
Zelin Li,Jiale Cai,Shaomin Zhou +2 more
TL;DR: Li et al. as discussed by the authors discovered a new kind of current oscillation during the reduction or oxidation of some anions, which appeared over the limiting reduction and oxidation current of the anions and was loaded on the current of hydrogen or oxygen evolution.
Journal ArticleDOI
Voltammetric response for the diffusion-controlled electrodeposition onto growing hemispherical nuclei
TL;DR: In this article, orthogonal collocation has been used to solve numerically the transient moving boundary problem for the voltammetric response of isolated hemispherical nuclei which are growing as a result of the diffusion of metal cations from solution and their electrodeposition at the surface.
Journal ArticleDOI
Bifunctional electrochemical systems
N D Ivanova,S V Ivanov +1 more
TL;DR: In this paper, the formation of a film having a mixed conduction type and consisting of oxide-hydroxide compounds of the metal denotes the presence of a new system: the electrode-film-electrolyte system, called a bifunctional electrochemical system because it can act an electrolyte and as an electrode simultaneously.
References
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Journal ArticleDOI
Adsorption behavior of polyoxyethyleneglycole on the copper surface in an acid copper sulfate bath
TL;DR: In this article, the effect of polyoxyethyleneglycole (PEG) on the copper deposition and dissolution was studied in an acid copper sulfate bath as a function of electrode potential, polymerization degree of PEG and Cl - concentrations.
Journal ArticleDOI
The electrochemical study of a chromium plating bath. I. Reactions leading to solution-free species
Jiang Lin-Cai,Derek Pletcher +1 more
TL;DR: In this paper, the I-E curve shows a wave or peak for the reduction of chromium (VI) to chromium(III) and it is demonstrated that this process is mass transport controlled, apparently by the transport of sulphate ions to the electrode surface.
Journal ArticleDOI
Redoxvorgänge an Elektroden in Gegenwart von Chromsäure
Heinz Gerischer,Mario Käppel +1 more
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The electrochemical study of a chromium plating bath. I. Reactions leading to solution-free species
Jiang Lin-Cai,Derek Pletcher +1 more