Formation and reduction of anodic film on polycrystalline Bi electrode in pure methanol solutions

Abstract

The processes of film formation and reduction of bismuth in pure methanol are phenomenologically studied by means of cyclic, ac voltammetric and electrochemical impedance spectroscopic methods. Film formation takes place under low electrode potentials within the potential range from -0.1 to about 0.2 V vs. Ag|AgCl resulting in the development of Bi(CH3O)ads layer. The scan rate effect on the anodic current profile is interpreted in terms of a gradual variation of uncompensated resistance, accompanying the processes of film formation and reduction. Phase sensitive ac voltammetry measurements suggest leaky insulating character of a thin anodic film in agreement with the results of electrochemical impedance experiments.