Electrochemical behaviour of silver in aqueous chromate solutions

The electrochemical behaviour of silver was studied under cyclic voltammetry and chronoamperometry conditions in aqueous K 2 CrO 4 solutions. The forward cyclic voltammograms exhibited one oxidation peak, A 1 , due to the formation of Ag 2 CrO 4 . The height of the anodic peak, A 1 , increases with increasing chromate concentration, temperature, and scan rate. The solid films formed on the anode surface have been examined by X-ray diffractometry. The reverse voltammograms exhibited two reduction peaks, C 1 and C 2 , indicating the formation of two distinct surface layers of Ag 2 CrO 4 , an inner compact layer reduced in peak C 1 and an outer powdery layer reduced in peak C 2 .Key words: silver electrode, cyclic voltammetry, K 2 CrO 4 solutions.