Elecrochemical Behaviour of Zinc on Copper and on Vitreous Carbon Electrodes: The Influence of Gluconate

The zinc electrochemical behaviour from sulphate and sulphate-gluconate baths was studied both on a vitreous carbon and a copper electrode. The voltammetric response depends on the complexing agent concentration, the electrode material, the pH and the cathodic potential limit. The reduction of zinc ions proceeds with hydrogen evolution, and at less negative potentials on the copper electrode than on the vitreous carbon electrode, specially in absence of gluconate. Gluconate decreases the efficiency of the process. On the other hand, gluconate favours zinc electrodeposition on vitreous carbon but retards it on copper.