PHOTOELECTROCHEMICAL CATALYSIS OF THE OXIDATION OF ORGANIC-MOLECULES BY OXYGEN ON SMALL SEMICONDUCTOR PARTICLES WITH TIO2 AS AN EXAMPLE

The kinetics of the photocatalytic oxidation of organic molecules at TiO2 particles are analyzed with the aim of determining the conditions required to obtain high quantum yields. With the assumption that holes react at the interface faster than electrons, the particles contain, in the steady state, an excess of electrons under illumination. It is shown that the rate of electron capture by oxygen is a decisive parameter for the yield. It also transpires that only very small particles can reach a high yield.