Electrochemical reduction of oxygen on anodically pre-treated and chemically grafted glassy carbon electrodes in alkaline solutions

The electrochemical reduction of oxygen on anodically pre-treated glassy carbon (GC) and on oxidised GC electrodes grafted with anthraquinone has been investigated using the rotating ring-disk electrode (RRDE) technique. Surface oxidation increases the electrocatalytic activity of GC for oxygen reduction to hydrogen peroxide. However, these electrodes catalyse the further reduction of HO2- at potentials more negative than approximately -0.9 V vs. SCE. The O-2 reduction behaviour is considerably altered when oxidised GC electrodes are grafted with anthraquinone. (C) 2003 Elsevier B.V. All rights reserved.