SrTiO3/TiO2 heterostructure 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 SrTiO3 nanocubes were in-situ grown on TiO2 nanowires to construct heterojunctions.The composites were prepared by a facile alkaline hydrothermal method and an in-situ deposition method.The obtained SrTiO3/TiO2 exhibits much better photocatalytic activity than those of pure TiO2 nanowires and commercial TiO2(P25)evaluated by photocatalytic water splitting and decomposition of Rhodamine B(RB).The hydrogen generation rate of SrTiO3/TiO2 nanowires could reach 111.26 mmol·g^−1·h^−1 at room temperature,much better than those of pure TiO2 nanowires(44.18 mmol·g^−1·h^−1)and P25(35.77 mmol·g^−1·h^−1).The RB decomposition rate of SrTiO3/TiO2 is 7.2 times of P25 and 2.4 times of pure TiO2 nanowires.The photocatalytic activity increases initially and then decreases with the rising content of SrTiO3,suggesting an optimum SrTiO3/TiO2 ratio that can further enhance the catalytic activity.The improved photocatalytic activity of SrTiO3/TiO2 is principally attributed to the enhanced charge separation deriving from the SrTiO3/TiO2 heterojunction.