Electrochemical studies on glassy carbon electrodes: IV. Influence of solution pH and buffer capacity on reduction of oxygen

Abstract

Linear sweep voltammetry on a glassy carbon electrode in oxygen-saturated solutions showed marked changes in current—potential behaviour at distinct pH values characteristic of the composition and buffer capacity of the solution. The changes are related to the conditions under which the pH at the electrode surface can rise rapidly to a value considerably higher than that in the bulk solution; they are observed on electrode materials (like glassy carbon) for which the mechanism of oxygen reduction is different at low and high pH, but not on wax-impregnated graphite or mercury cathodes.