Direct Observation of Reactive Trapped Holes in TiO_2 Undergoing Photocatalytic Oxidation of Adsorbed Alcohols: Evaluation of the Reaction Rates and Yields

摘要

TiO_2 is a highly active photocatalyst that has an antibacterial function and is used for applications such as air purification and surface self-cleaning.The photocatalytic activity of TiO_2 is mainly due to the oxidation power of photogenerated holes in its valence band.Hole transfer to a molecule adsorbed on the TiO_2 surface initiates the oxidation reaction,and the oxidized molecule changes into a final product through sequential chemical events.In photo-catalytic reactions,TiO_2 reacts with an adsorbed molecule at the first step of oxidation using the holes; therefore,to understand the mechanism of photocatalytic reaction of TiO_2,it is very important to investigate the hole transfer processes.