MECHANISM OF THE REVERSE DISSOLUTION OF ZINC IN THE PRESENCE OF NICKEL .1. INFLUENCE OF ANODIC PRODUCTS AND SUBSTRATE PURITY

From galvanostatic potential-time curves, voltammograms and impedance measurements, it is shown that the destabilization of the zinc deposit ion process by Ni2+ ions present in the acidic sulphate electrolyte is considerably favoured in the absence of a diaphragm separating the an ode and cathode compartments. It is concluded that the deleterious inf luence of Ni2+ ions is enhanced by the anodically formed products whic h interfere with the slow interfacial processes taking place at the ca thode surface. A stronger synergetic influence of nickel and oxidized species is demonstrated when using an aluminium cathode containing Fe impurities.