Elucidation of the electron energy structure of TiO(2)(B) and anatase photocatalysts through analysis of electron trap density

A clear understanding of the electron energy structure of TiO(2)(B)/anatase is needed to study the related catalytic reactions and design new composite photocatalysts. In this study, the electron energy structures of TiO(2)(B) and anatase were estimated by analyzing the energy-resolved distribution of electron traps measured by reversed double-beam photoacoustic spectroscopy. In the mixture of TiO(2)(B) and anatase, interfacial charge-transfer excitation from anatase to electron traps of TiO(2)(B) was suggested. By analyzing this for TiO(2)(B), the electron level with a relatively high density of states was found to be located ∼0.07 eV deeper than that for anatase. Furthermore, a similar electron energy structure was suggested for a composite photocatalyst having a mixed phase of TiO(2)(B) and anatase.