Control of electron transfer kinetics of organic redox systems on carbon electrodes

摘要

A kinetic analysis for determining the surface characteristics which control electron transfer rates at carbon surfaces was extended to a wider range of reactions including organic redox systems. Chlorpromazine and methyl viologen were found to behave as outer sphere systems on glassy carbon, showing minor effects of surface modification on electron transfer. Dopamine and related catechols behaved quite differently, with surface modification profoundly affecting kinetics. Dopamine was completely inactive on modified glassy carbon unless it could adsorb to the surface. The possible mechanisms of these effects are discussed.