Mechanism of Cathodic Potential Oscillations of the Zinc Electrode in Alkaline Solutions

A detailed investigation of the mechanism of cathodic potential oscillations of zinc in alkaline solutions is described and analyzed here. The oscillation period is divided into three successive times, each corresponding to a particular phenomenon, which are defined as: the depletion, supersaturation, and recovery time. They are studied experimentally using chronopotentiometric recordings over a large range of conditions (−0.0055 to −0.17 A/cm2 and 0.15–0.9 mmol/cm3 in 8.4 mmol/cm3 aqueous at room temperature) and the results are analyzed theoretically. The nature and relative importance of the different overpotentials are determined and discussed during each one of the three times occurring in each period. The controlling mechanism for both the zinc reaction and zinc complex ion transport is thus deduced and discussed.