Square-Wave Voltammetry of Quasi-Reversible CE Reactions at Spherical Microelectrodes

F. GARAY; M. LOVRIC

WILEY-V C H VERLAG GMBH

Lugar: New York; Año: 2002 vol. 14 p. 1635 - 1635

A mathematical model for the CE mechanism in which the chemical together with the electrochemical reactions are quasi-reversible at the surface of spherical macro and micro-electrodes is presented for the case of square-wave voltammetry. The analysis of voltammometric responses considers the influence of rate and equilibrium constants, together with the electrode radius, and their dependence on the square-wave frequency (f). Both kinetics and the sphericity effect act synergistically on the electrochemical response. Also, the apparent electrode sphericity and the reversibility of the chemical as well as the electrochemical reactions are jointly affected by the variation of f. Disregarding the sphericity contribution in the calculation of kinetic parameters at a microelectrode may introduce errors even higher than one order of magnitude. The model allows the analysis of a more realistic and complex electrochemical system that requires not only the dependence of experimental response