SrTiO3/TiO2heterostructure nanowires with enhanced electron-hole separation for efficient photocatalytic activity

Heterostructure is an effective strategy to facilitate the charge carrier separation and promote the photocatalytic performance. In this paper, uniform SrTiO3nanocubes were in-situgrown on TiO2nanowires to construct heterojunctions. The composites were prepared by a facile alkaline hydrothermal method and an in-situdeposition method. The obtained SrTiO3/TiO2exhibits much better photocatalytic activity than those of pure TiO2nanowires and commercial TiO2(P25) evaluated by photocatalytic water splitting and decomposition of Rhodamine B (RB). The hydrogen generation rate of SrTiO3/TiO2nanowires could reach 111.26 mmol·g−1·h−1at room temperature, much better than those of pure TiO2nanowires (44.18 mmol·g−1·h−1)and P25 (35.77 mmol·g−1·h−1). The RB decomposition rate of SrTiO3/TiO2is 7.2 times of P25 and 2.4 times of pure TiO2nanowires. The photocatalytic activity increases initially and then decreases with the rising content of SrTiO3, suggesting an optimum SrTiO3/TiO2ratio that can further enhance the catalytic activity. The improved photocatalytic activity of SrTiO3/TiO2is principally attributed to the enhanced charge separation deriving from the SrTiO3/TiO2heterojunction.