3^rd World Chemistry Conference

Biography

Biography: Iason Rusodimos

Abstract

Theoretical expressions for the first, second and third derivatives of voltammetric curves are analytically derived for reversible, quasi-reversible, and irreversible processes under spherical diffusion. The shapes of the curves are analyzed in terms of peak-potentials, peak-currents, and peak-widths, and the differences and ratios among them. The results obtained with spherical electrodes are compared with those with the planar electrodes, which exhibits striking differences between two electrodes. Derived parameters – such as ratios of peak-currents (i^a_p/i^c_p), and ratios of half-peak-widths (W^a_½/W^c_½), and ratios of the differences in peak potentials (ΔE^a_p/ΔE^c_p), for various derivatives are analyzed. As electrode sphericity increases, these ratios (i.e., measures of symmetry in the curves) for a quasi-reversible and irreversible electron transfer process approaches to one, which is the same as that for a simple reversible electrode process on a planar electrode. Namely, the asymmetry which was exhibited on planar electrodes for quasi and irreversible processes disappears on a spherical electrode. This suggests that the planar electrode is better suited for kinetic study of slower electron transfer than spherical electrodes for this derivative approach.