Electrode Kinetics of the Ti(IV)/Ti(III) System in Water and in WaterDimethylformamide and WaterDimethyl Sulfoxide Mixed Solvents

Abstract

The electron transfer rate constants in the reduction of Ti4+ and oxidation of Ti3+ in water and in water DMF and water DMSO mixtures were determined by square-wave polarography and by analysis of the DC and pulse polarographic curves. The two reactions occur at different potentials due to the rapid consecutive transformation of the primary product of the electrode reaction. Thus the rate constants are no standard rate constants, and depend on the method employed. The effect of the organic co-solvent varies for both reactions as a consequence of dependence of the degree of electrode coverage on potential. Generally, the adsorbed organic substance exerts an accelerating catalytic effect.