InVO4 nanocrystal photocatalysts: Microwave-assisted synthesis and size-dependent activities of hydrogen production from water splitting under visible light

The efficiency of visible-light-driven oxide semiconductor photocatalysts for hydrogen production from water splitting has long been restricted by the large particle size. In this study, a simple and versatile microwave-assisted synthesis of InVO 4 nanocrystal photocatalysts is proposed. The as-prepared products possess high crystallinity and ultra-small size (20   nm) that has never been reported yet. The 20   nm-sized nanocrystal samples show reduced visible-light response and enlarged reductive energy compared with large-sized InVO 4 samples. The hydrogen production rate of InVO 4 nanocrystal photocatalysts is 14.16   μmol   h −1   g −1 which is higher than that of large-sized InVO 4 microspheres (9   μmol   h −1   g −1 ). The model of size-dependent activities and the possible mechanism for the activity enhancement are also discussed by the band position calculation in this paper.