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 SrTiO 3 nanocubes were in-situ grown on TiO 2 nanowires to construct heterojunctions. The composites were prepared by a facile alkaline hydrothermal method and an in-situ deposition method. The obtained SrTiO 3 /TiO 2 exhibits much better photocatalytic activity than those of pure TiO 2 nanowires and commercial TiO 2 (P25) evaluated by photocatalytic water splitting and decomposition of Rhodamine B (RB). The hydrogen generation rate of SrTiO 3 /TiO 2 nanowires could reach 111.26 mmol·g −1 ·h −1 at room temperature, much better than those of pure TiO 2 nanowires (44.18 mmol·g −1 ·h −1 )and P25 (35.77 mmol·g −1 ·h −1 ). The RB decomposition rate of SrTiO 3 /TiO 2 is 7.2 times of P25 and 2.4 times of pure TiO 2 nanowires. The photocatalytic activity increases initially and then decreases with the rising content of SrTiO 3 , suggesting an optimum SrTiO 3 /TiO 2 ratio that can further enhance the catalytic activity. The improved photocatalytic activity of SrTiO 3 /TiO 2 is principally attributed to the enhanced charge separation deriving from the SrTiO 3 /TiO 2 heterojunction.