Monitoring the formation and decay of singlet molecular oxygen in TiO 2 photocatalytic systems and the reaction with organic molecules

Abstract

By monitoring the time profiles of 1O2 at the 1270-nm band, the reaction of singlet molecular oxygen (1O2) with four kinds of organic molecules, methionine, pyrrole, collagen, and folic acid was examined in photocatalytic systems of TiO2 aqueous suspension. A fast decay observed in 1.5 μs after the pulse excitation attributable to the fast reaction of formed 1O2 with these molecules. From the analysis of the decay profiles, it is concluded that the organic molecules should be adsorbed on the TiO2 surface to react with 1O2.