The influence of the real structure of the electrode surface on capacitive and faradaic effects in the electrode process

Abstract

The true surface area of single-crystal Ag( hkl) electrodes was determined using various electrochemical methods (the chronopotentiometric method, the underpotential electrosorption of metal cations and anodic oxidation) and two methods for measuring the capacitance of the double layer (phase shift measurements and chronovoltammetry). The mean index k of the surface development of single-crystal Ag( hkl) electrodes modified by epitaxial silver layers relative to the chemically polished Ag( hkl) surface was determined. Comparison of the values of k obtained using various electrochemical methods showed that the heterogeneous nature of the real structure of the single-crystal substrate is the cause of changes in the magnitude of the electrochemically active electrode surface area, depending on whether the electrode processes are faradaic or capacitive.