ELECTROCHEMICAL CHARACTERISTICS OF POLY(O-PHENYLENDIAMINE) FILM ELECTRODES IN PHOSPHATIC SOLUTION

The electrochemical characteristics of poly(o-phenylendiamine) (POPD) film modified electrodes have been investigated using different electr ochemical techniques. The main interest is focused on the effect of po tential and film thickness on the electrode process. Good agreement ha s been found for the apparent diffusion coefficient estimated by chron ocoulometry and impedance spectroscopy. The charge transfer process wi thin POPD films is diffusion processes at negative and positive overpo tentials and electron hopping mechanism at formal potential. The POPD film conductivity of the oxidized state is better than that of the red uced state. For all electrode processes, the H+ may penetrate the film /electrolyte interface and take part in charge transfer or protonation -deprotonation of phenazine rings.