The mathematical models of the stripping voltammetry metal deposition/dissolution process

Modeling of the Simultaneous Hydrogen Evolution and Cobalt Electrodeposition

A mathematical model of simultaneous cobalt deposition and hydrogen evolution was developed and applied to the electroreduction process of 5 mM Co 2+ ions investigated by cyclic voltammetry (CV) technique at different hydrogen ion concentrations (pH = 2, 3, 4). The kinetic parameters of such a complex process were determined, and the validity of the model and its sensitivity to changes in individual parameters were verified. The relative value of the approximate standard deviation (ASD % ) was used to determine the degree of fit of the model to the experimental data. The catalytic effect of cobalt on the hydrogen evolution process was comprehensively confirmed.

Copper Electrodeposition from Deep Eutectic Solvents-Voltammetric Studies Providing Insights into the Role of Substrate: Platinum vs Glassy Carbon

We report on the effect of the substrate on electrochemical deposition of Cu from deep eutectic solvent ethaline. We investigated the polarization behavior during electrodeposition of Cu on Pt and glassy carbon (GC) from both Cu²⁺ and Cu⁺ containing ethaline using cyclic voltammetry (CV). Formation of bulk Cu deposits on both substrates underwent nucleation and growth processes; however, the nucleation was considerably sluggish on GC compared to Pt. While experiments in Cu⁺ solutions indicated that coalescence of Cu islands on Pt is a slow process and that its surface may not be fully covered by Cu, such determination of Cu coverage could not be made on GC. Cu dissolution is also slower from GC than from Pt. It was observed that CV of Cu deposition on GC is influenced by the surface preparation method. Since ethaline has high chloride concentration, a parallel study in aqueous 3 M NaCl solution was conducted in order to examine the influence of the chloride medium on the electrodeposition process. This revealed that electrodeposition in both media occurred in the same manner but with different charge and mass transfer rates caused by the differences in viscosity and chloride concentrations of the two solutions.