Observing the electrochemical interphase via electrode surface conductance

Abstract

A method has been developed for studying the electrochemical interphase which is straightforward, easy to use, and can be applied to various electrode processes. Measuring the conductance of a thin film electrode has provided new information about the electrode surface. On the basis of this method the conductance of a thin film can be monitored and the change in surface charge density of the electrode calculated. Conductance changes can be used to separate the faradaic current from the charging current since only the charging current will affect the conductance. Ion adsorption can easily be detected, thus providing a new method for studying reaction processes at the electrode surface. Reflectance measurements, which are independent, have been used together with conductance in detecting electrochemical processes in the double layer region and electrode surface. A good example is the definite change in the adsorption process on the gold electrode around pH 4, where the conductance varies independently of the reflectance, but which is difficult to detect just by observing the electrode current. Thus, conductance measurements provide another independent method to unravel the complex reactions occurring at the electrode-electrolyte interface.