Mechanistic investigations of redox polymer-coated electrodes using probe-beam deflection and cyclic voltammetry

Optical probe-beam deflection signals, together with cyclic voltammograms, have been used to analyse the electron-transfer process at electrodes coated with [Ru(bpy)2ClPVP]Cl, polyaniline and poly(1-hydroxyphenazine). With this technique it is possible to determine if anions or cations are used as the charge-compensating ions in the electron-transfer process. The electron transfer at [Ru(bpy)2ClPVP]Cl was shown to be accompanied by a simple counter-ion diffusion process. The known electron-transfer mechanism of polyaniline was confirmed and a plausible mechanism for the electron transfer of poly(l-hydroxyphenazine) has been proposed. The additional information (direction of concentration gradients) obtained by a simple probe-beam deflection experiment is extremely useful in the analysis of reaction mechanisms at redox polymer-coated electrodes.