Extrazeolite electron transfer at zeolite-encapsulated polypyridyl metal complex coated electrodes

Abstract

The electrochemical response of highly boron-doped conductive diamond electrodes to Ce³⁺ ions in aqueous sulfuric acid, nitric acid and perchloric acid solutions was studied mainly by use of cyclic voltammetry. The diamond electrode shows a well-defined voltammogram indicating quasi-reversible behavior for the Ce³⁺/Ce⁴⁺ redox couple in aqueous acidic solution. The equilibrium redox potential of the Ce^3+/4+ couple was derived from the cyclic voltammograms. The diffusion coefficients for Ce³⁺ were evaluated from the dependence of the cyclic voltammograms on the potential sweep rate. The kinetic parameters for the anodic oxidation of Ce³⁺ were measured at the diamond electrode from the relation between the overpotential and the logarithm of current.