Anodic oxidation of silver and Ag-Au alloys in alkaline medium

Anodic oxidation of Ag and Ag-Au alloys containing from 0.1 to 30 at. % Au under the conditions of Ag(I) oxide formation at t greater than or equal to 0.5 s is determined by the peculiarities of migration transfer of charge carriers through phase oxide layer. The Ag2O film is two-layer; this is reflected in the rise of additional current peaks in cyclic i vs. E(t) curves and also in the variation in the slopes of linear segments of chronoammograms presented in the i vs. t(-1/2) coordinates. The conductivity of Ag2O film Slightly varies with its thickness; it is virtually independent of small gold additions to silver, but steeply decreases at 15 and 30 at. % An. The formation and reduction of AgO occur via single-electron conversions of Ag2O proceeding in the oxide phase. At all stages of oxidation of Ag and Ag-Au alloys in alkaline medium, the charge-transition stage remains reversible.