Quasi-reversible EC reactions at spherical microelectrodes analysed by square-wave voltammetry

F. GARAY; M. LOVRIC

ELSEVIER SCIENCE SA

Lugar: Amsterdam; Año: 2002 vol. 527 p. 85 - 85

mathematical model for a quasi-reversible EC mechanism at the surface of spherical macro- and micro-electrodes is presented for the case of square-wave voltammetry. The analysis considers the influence of the chemical and the electrochemical kinetics as well as the contribution of sphericity to the voltammetric responses. The apparent electrode sphericity and the global apparent reversibility are jointly affected by the variation of frequency (f ). If the electrode radius (ro) is smaller than 30 mm, but the sphericity contribution is neglected, it is not possible to obtain good kinetic information. For Esw > 0.2 V the system is shifted far from the steady-state and the kchem value can be analysed regardless of the ks value. However, for Esw = 50 mV, it is not possible to evaluate kchem if ks < 1000 or K > 1. Simple equations for the dependence of DCp on f , ro and Esw have been provided. Nevertheless, the analysis of such complex electrochemical systems should require not on