Specific Features of the Initial Stages of Oxidation of a Silver Electrode in Weakly Acidified Solutions of Sodium Fluoride

The behavior of a silver electrode, which is renewed in situ by mechanical cutting, in weakly acidified sodium fluoride solutions is studied with the aid of an impedance method and a method of cyclic voltammetry. The application of said procedures makes it possible to record time effects, which reflect the processes of electrochemical adsorption of oxygen at the interface between the silver electrode and the solution, in the potential region extending from −0.7 to 0.2 V (SCE). Approximate calculations of the effect of potential and the time of the electrode’s exposure (after its renewal) in contact with the electrolyte at given values of potential on the amount of adsorbed oxygen are performed on the basis of an analysis of the obtained experimental data. A comparison of the obtained results with the literature data makes it possible to put forth a substantiated opinion as to the reasons for the substantial difference in the intervals of potentials of ideal polarizability of the silver electrode/solution of a surface-inactive electrolyte system, which are presented in works of various authors.__________Translated from Elektrokhimiya, Vol. 41, No. 7, 2005, pp. 857–865.Original Russian Text Copyright © 2005 by Safonov, Choba, Oshkin.