Intrinsic intermediate gap states of TiO2 materials and their roles in charge carrier kinetics

Publication date: Available online 5 March 2019Source: Journal of Photochemistry and Photobiology C: Photochemistry ReviewsAuthor(s): Baoshun Liu, Xiujian Zhao, Jiaguo Yu, Ivan P. Parkin, Akira Fujishima, Kazuya NakataAbstractTitanium dioxide (TiO2) is regarded as an important prototype photocatalytic material for several decades. The charge carrier kinetics determines the photocatalytic properties of TiO2 materials; this is found to be greatly dependent on electronic structures. It has been revealed that the intrinsic intermediate gap states (intrinsic GSs) play a significant role in charge carrier kinetics that drive the photocatalytic processes of TiO2 materials, which are not well summarized until now. Motivated by this thought, the purpose of this review focuses on physiochemical science of the intrinsic GSs of TiO2 materials and their important role in charge carrier kinetics. We first give a summary on the chemical resources of the intrinsic GSs in TiO2 and their physiochemical nature. Their general energy distribution, charge carrier population, and the associated thermodynamic properties are also elaborated from an overall viewpoint. We further carefully summarise and compare the experimental studies on the energy and the density distribution of the intrinsic GSs and discuss the associated chemical resources and charge carrier localizations. Trapping is the dominant function of intrinsic GSs in the charge carrier kinetics of TiO2 materials. The significant effect of ...

Source: Journal of Photochemistry and Photobiology C: Photochemistry Reviews - March 5, 2019 Category: Chemistry Source Type: research