Monitoring the Formation and Decay of Singlet Molecular Oxygen in TiO₂ 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.