Femtosecond Diffuse Reflectance Spectroscopy of Aqueous Titanium(IV) Oxide Suspension: Correlation of Electron-Hole Recombination Kinetics with Photocatalytic Activity

Abstract
Pump-probe diffuse reflectance measurements were carried out on particulate titanium(IV) oxide photocatalysts in the form of aqueous suspension and dry powder. A linear relation between second-order rate constants of electron-hole recombination for the suspension and powder systems was seen by analyses of decay profile of charge carriers. Presence of air gave negligible effect on the recombination kinetics, but loading of platinum (Pt) significantly reduced the rate constant.