Highly efficient SnS2@Ag/AgVO3 heterostructures for improved charge carriers in photocatalytic H2 production

Abstract

Ternary nanostructures are promising candidates for hindering the rapid recombination of photoexcited electron-hole pairs for photocatalytic H2 production. Herein, the enhanced charge carrier separation and improved visible-light absorption capability of the ternary geometry of Ag/AgVO3 with SnS2 is described. SnS2 @Ag/AgVO3 heterostructures were fabricated via a hydrothermal process, and H2 generation was achieved using a solar light source and a lactic acid-water mixture. The formation of the SnS2@Ag/AgVO3 heterostructures was confirmed by spectroscopic and microscopic analyses. The SnS2@Ag/AgVO3 material showed higher photocatalytic H2 performance (2802 µmol/g/h) and quantum efficiency compared to that of SnS2 (215 µmol/g/h) under solar light irradiation. It also exhibited long-term stability for eight repetitive cycles, after which the performance slightly declined. This enhancement in the water splitting activity of SnS2@Ag/AgVO3 was ascribed to the maximized interfacial contact between SnS2 and Ag/AgVO3, and the high visible-light absorptivity and efficiency of the photoinduced electron-hole pairs derived from SnS2 in the heterostructures. The SnS2@Ag/AgVO3 heterostructures were tested for H2 generation, and a possible charge-carrier separation process and photocatalytic mechanism are suggested. Accordingly, a useful strategy for fabricating a visible-light-harvesting SnS2@Ag/AgVO3 heterostructure for solar energy conversion to H2 fuel is presented.