Effect of potential on the early stages of nucleation and growth during cobalt electrocrystallization in sulfate medium onto FTO surface

The electrodeposition of Co thin films onto a fluorine-doped tin oxide (FTO)-coated conducting glass substrate from sulfate solutions was investigated using cyclic voltammetry, and chronoamperometry measurements. The Scharifker and Hills model was used to analyze current transients. At relatively low overpotentials, the Co deposition can be described by a model involving instantaneous nucleation on active sites and diffusion-controlled 3D growth. The values of kinetic parameters, number density of active sites N∞, and diffusion coefficient D for Co2+ ions are also calculated.