Determination of standard electrochemical rate constants from semi-circular sweep voltammetry: A combined theoretical and experimental study

Abstract Semi-circular potential sweep voltammetry has recently been proposed as a sensitive method to estimate electrochemical rate constants [J. Electroanal. Chem., 835 (2019) 60–66]. Herein, this approach is experimentally verified using microdisc electrode voltammetry. The reduction of hexaamineruthenium (III) chloride and the oxidation of ferrocenemethanol, both in aqueous solution, at carbon electrodes were studied. The rate constants obtained from semi-circular voltammetry for both investigated redox systems are in agreement with independent values obtained from the conventional Nicholson method at macroelectrodes. The method compares favourably in terms of simplicity and speed as it requires recording only a single voltammogram. This approach provides a novel, fast complementary method for the evaluation of the standard electrochemical rate constant.