Density Functional Characterization of the Electronic Structures and Band Bending of Rutile RuO2/TiO2(110) Heterostructures

摘要

The enhanced catalytic and photocatalytic activities of a RuO2 layer deposited on the TiO2(110) surface were examined by constructing model RuO2/TiO2(110) heterostructures with and without oxygen vacancies and performing density functional calculations. The formation of the heterojunction only weakly affects the atomic structure of the interface due to a pseudomorphic deposition but causes a strong electron density accumulation in the interface as well as a bending of the valence and conduction bands of TiO2. The electron accumulation in the interface creates a strong internal electric field, which helps to effectively separate photogenerated electron-hole pairs during a photocatalytic process. Finally, we report on catalytic role of oxygen vacancies at the surface.