Effect of defects on photocatalytic dissociation of methanol on TiO2(110)

Abstract

Photocatalytic dissociation of deuterated methanol (CD₃OD) on both stoichiometric and reduced TiO₂(110) surfaces was investigated using the time-dependent two-photon photoemission (2PPE) method, in order to understand the effect of defects on the kinetics of methanol dissociation on TiO₂(110). By monitoring the time evolution of the photoinduced excited state on the methanol covered surface, the photocatalytic dissociation kinetics of methanol on the TiO₂ surface were observed. The measured photodissociation rate on the reduced TiO₂(110) surface is more than an order of magnitude faster than that on the stoichiometric surface. Since the reduced TiO₂(110) surface has considerably more surface and subsurface defects than the stoichiometric surface, the experimental observation suggests that one or both of them could accelerate the photocatalysis process of methanol on the TiO₂(110) surface in a significant way.