Photocatalytic Oxidation of Alcohols on TiO2

Abstract
The reaction mechanisms of the photocatalytic oxidation of several different alcohols on TiO2 were investigated by three experimental techniques: spin trapping, photocurrent measurement, and product analysis. The results are interpreted according to the band model of a semiconductor and current doubling. It was found that alcohols with α-hydrogens gave low concentrations of spin adducts since their photoproduced radicals have short lifetimes on TiO2 due to a current-doubling process. Also, it was found that oxygen participated in a radical chain mechanism in the photocatalytic oxidation of ethanol to acetaldehyde.