Electrochemical and AFM studies of the electrodeposition of cobalt on glassy carbon: an analysis of the effect of ultrasound

摘要: Abstract The mechanism of cobalt electrodeposition on glassy carbon from an aqueous sulphate solution has been studied using electrochemical techniques such as cyclic voltammetry, linear stripping voltammetry (LSV) and chronoamperometry, well contact mode atomic force microscopy (AFM) which allowed the complementary determination morphological detail resulting deposits. influence power ultrasound (20 kHz) was then studied. At suitably high overpotentials electrocrystallisation under silent conditions proceeds via a diffusion controlled analysed Scharifker Hills model for potentiostatic growth: at low (ca. −1.0 V vs. SCE) growth occurred charge transfer control. Nucleation found to be more ‘progressive’ in character SCE while elevated (more negative than −1.25 V) ‘instantaneous’ nucleation behaviour determined. Sonication favoured deposition generally increased rate deposition, although ablation dominant small electrode—tip/horn separations. AFM images confirmed these findings, showing clusters varying sizes overpotential conditions, uniformly sized higher overpotentials, particularly when sonication applied.