Infrared absorption photocatalysts Hiroshi Onishi by electrons excited in doped

Abstract

Doping with hetero-elements provides a common and efficient way to sensitize wide-bandgap photocatalysts to visible light. It is important to know how the dopants positively affect catalytic performances. We have been studying photo-induced dynamics using time-resolved infrared (IR) absorption spectroscopy. Electrons are excited in a photocatalyst by pulsed light irradiation. The excited electrons exhibit the absorption of mid-IR light. The decay of the IR absorbance is related to the kinetics of electron-hole recombination in the bulk and electron-consuming reactions at the surface. In the current talk, the rate of electron-hole recombination is quantitatively compared with the steady-state rate of H2 production on doped NaTaO3. The identity of the initial state of IR absorbing transition is also discussed.