The preparation and electrochemical characterization of glassy carbon electrodes modi®ed by some recently synthesized anthraquinone substituted podands were investigated. These compounds were found to be strongly and irreversibly adsorbed on the preanodized glassy carbon electrodes. The electrochemical behavior and stability of the modi®ed electrodes were studied by cyclic voltammetry in acidic aqueous solutions. The in¯uence of pH on the electrochemical behavior of the electrodes was studied and a pH of 4.5 was chosen as the optimum working pH. The ability of the modi®ed electrodes as potential electrocatalysts for the reduction of dioxygen to hydrogen peroxide was tested by cyclic voltammetry, chronomperometry and rotating disk electrode voltammetry. They showed excellent electrocatalytic ability for the reduction of O2 at pH 4.5 with overpotentials ranging from 380 to 470mV lower than the plain glassy carbon electrode. The heterogeneous rate constants for the reduction of O2 at the surface of these modi®ed electrodes were determined by the use of Koutecky- Levich plots. In addition, the apparent diffusion coef®cients of O2 in buffered aqueous O2-saturated solution was estimated.

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