Oxygen reduction on thick anthraquinone films electrografted to glassy carbon

Multilayer 9,10-anthraquinone (AQ) films on the surface of glassy carbon (GC) electrodes were prepared by electrochemical reduction of the corresponding diazonium cations in acetonitrile. The surface concentration of AQ was varied in the range of (1-6) × 10−9 mol cm−2 using different modification procedures. X-ray photoelectron spectroscopy (XPS) was used to analyse the composition of AQ films. The XPS study revealed the presence of azo linkages within the film. The oxygen reduction reaction was investigated employing the rotating disk electrode (RDE) method. The RDE results indicated that the reduction of oxygen follows a two-electron pathway on thick AQ films.