Correlate between morphology of powder particles obtained by the different regimes of electrolysis and the quantity of evolved hydrogen

Abstract

Morphologies of copper powder particles obtained by both potentiostatic and pulsating overpotential (PO) regimes of electrolysis were investigated by the technique of scanning electron microscopy (SEM). Particles of dendritic or cauliflower-like shape were formed in the dependence of the selected parameters of square-waves PO. The obtained particles were compared with those obtained in the constant potentiostatic regime from solutions of different CuSO4 and H2SO4 concentrations. It was shown that the effect of the decreasing deposition pulse was equivalent to the increasing CuSO4 concentration. Pause duration was equivalent to the used concentration of H2SO4, while the overpotential amplitude in the PO regime corresponded to the overpotential of electrodeposition in the constant potentiostatic mode. Morphologies of powdered deposits were grouped in the three hydrogen co-deposition ranges and their formation was discussed in the dependence of the quantity of hydrogen generated at the cathode surface during electrochemical deposition processes.