The Mechanism of Silver(I) Oxide to Silver(II) Oxide Formation on Polycrystalline Silver Electrodes in 8 M KOH Solution

The kinetics of silver(II) oxide formation on polycrystalline silver electrodes in 8 M KOH solution was investigated by cyclic voltammetry, potentiostatic and galvanostatic techniques, and by the morphology of the silver(II) oxide structures determined by scanning electron microscopy. Potentiostatic investigations revealed unambiguously that the silver(II) oxide formation proceeded via a nucleation and 3-D growth process. Microscopic examinations provided undoubted evidence that nucleation, 3-D growth, and Ostwald ripening processes are involved in the stage of silver(II) oxide formation. In addition, it was found that two types of silver(II) oxide morphologies might be formed by progressive and instantaneous nucleation process in the silver(I) oxide layer covering the silver substrate.