On Room-Temperature Electrodeposition of Cobalt from a Deep Eutectic Solvent: A Study of Electronucleation and Growth Mechanisms

This paper demonstrates the capability of the cobalt electrodeposition from a eutectic mixture of choline chloride and urea at room temperature. Thermodynamic and kinetic aspects of cobalt electronucleation and growth mechanisms onto glassy carbon electrode were investigated. The cobalt electrodeposition, at 303 K, is dominated by progressive nucleation. The behavior of current density transients of the Co electrodeposition can be described by a model comprising the contribution due to three-dimensional nucleation and diffusion-controlled growth from metallic nuclei combined with the effect of the induction – time. The diffusion coefficient of cobalt ions in deep eutectic solvent was determined by cyclic voltammetry and best-fit parameters obtained using the proposed model. Both values were in agreement with the results published in the literature. SEM and EDS verified the presence and the nucleation type of cobalt onto glassy carbon electrode.