engleski

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

A mathematical model for quasi-reversible EC mechanism at the surface of spherical macro-and micro-electrodes in presented for the case of square-wave voltammetry. The analysis considers the influence of the chemical and the electrochemical kinetics as well as contribution of sphericity to the voltammtric responses. The apparent electrode sphericity and the global apparent reversibility are jointly affected by the variation of frequency (f). If the electrode redius (r0) is smaller than 30mikrom, but the spericity contribution is neglected, it is not possible to obtain good kinetic information. Za Esw > 0.2 V the system is shfted 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 < 10-3 or K>1. Sample equations for the dependence on f , ro Esw have been provided.

square-wave voltammetry ; simulation ; coupled chemical reaction ; mechanistic studies ; spherical microelectrodes

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