Electroreduction of peroxodisulfate anions as a probe reaction for studying passivation of solid gallium in sulfate media

The kinetics of reduction of peroxodisulfate anions is studied on a rotating disk electrode made of gallium in sulfate solutions using the methods of linear voltammetry, chronoamperometry, and chronopotentiometry. The reduction process is shown to be complicated by the formation of an anodic film on the electrode from the products of oxidation and hydrolysis of Ga(III). Based on the results of the analysis of the data obtained, a structural model of the anodic film formed in the initial stages of Ga passivation is suggested and substantiated. It is assumed that the method of probe reactions (in our case, electroreduction of S2O82- anions) can be recommended for studying the metal passivation in different media.