Cobalt electrodeposition onto polycrystalline gold from ammoniacal solutions

In the present work, the cobalt electrodeposition onto polycrystalline gold electrodes from aqueous solutions containing 0.01M CoSO4+ 1 M (NH4)2SO4 at pH=7 was analyzed. Linear voltammetry results suggested a change in the kinetic of the cobalt electrodeposition. In all cases, the nucleation rate (A), the number of active nucleation sites (N 0) and the saturation number of nuclei (N s ) values were potential dependent. The calculated Gibbs free energy (?G) for this system was 1.88×10?20 J nuclei?1 and the transfer coefficient for the Hydrogen Electroreduction Reaction (HER) was 0.47.