Exploring crystal phase and morphology in the TiO2 supporting materials used for visible-light driven plasmonic photocatalyst

Abstract

The effects of crystal phase and morphology in TiO2 on photocatalytic performance under visible light were experimentally and theoretically investigated. Results reveal that a rutile crystal phase with a three dimensional (3D) morphology was the most favorable supporting material for visible light driven photocatalyst among Au/TiO2s. The prolonged localized surface plasmon resonance (LSPR) lifetime and plasmonic coupling of Au induced by the 3D morphology of TiO2 played a key role in enhancing photocatalytic activity. In addition, hot electrons generated on Au by LSPR are preferentially transferred to rutile TiO2 due to the overlapping of density of states (DOS) of Au in the conduction band of rutile TiO2 but obstruction of the reverse directional transfer of electrons to Au by large band bending. Our results provide a strategy for designing suitable plasmonic photocatalysts based on the crystal phase and morphology of TiO2 for solar light-driven photocatalysis applications.