Voltammetric response and electrochemical properties of the O2/O 2 •− couple in acetone

Abstract

Voltammetric responses of the O2/O2•− couple as a function of aprotic solvents are investigated. The results show that acetone is a suitable solvent for examining the electrode reaction of the O2/O2•− couple. Studying the electrochemical behavior of the O2/O2•− couple at different electrodes in acetone by cyclic voltammetry suggests that the reversibility of the O2/O2•− couple and the redox peak currents at glassy carbon are better than those at gold and platinum. The kinetic parameters (electron transfer rate constant k0 and cathodic transfer coefficient α) of the oxygen reduction to superoxide ion (O2•−) are evaluated using normal-pulse voltammetry. The obtained values of k0 (cm/s) and α are (1.95 ± 0.05) × 10−4 and 0.34 ± 0.01, respectively. The scavenging activities of ascorbic acid and bilirubin are tested and the experimental results confirm that ascorbic acid is a better scavenger toward O2•−.