Efficient Photocatalytic Hydrogen Evolution via Band Alignment Tailoring: Controllable Transition from Type-I to Type-II.

Considering the sizable band gap and wide spectrum response of tin disulfide (SnS2 ), ultrathin SnS2 nanosheets are utilized as solar-driven photocatalyst for water splitting. Designing a heterostructure based on SnS2 is believed to boost their catalytic performance. Unfortunately, it has been quite challenging to explore a material with suitable band alignment using SnS2 nanomaterials for photocatalytic hydrogen generation. Herein, a new strategy is used to systematically tailor the band alignment in SnS2 based heterostructure to realize efficient H2 production under sunlight. A Type-I to Type-II band alignment transition is demonstrated via introducing an interlayer of Ce2 S3 , a potential photocatalyst for H2 evolution, between SnS2 and CeO2 . Subsequently, this heterostructure demonstrates tunability in light absorption, charge transfer kinetics, and material stability. The optimized heterostructure (SnS2 -Ce2 S3 -CeO2 ) exhibits an incredibly strong light absorption ranging from deep UV to infrared light. Significantly, it also shows superior hydrogen generation with the rate of 240 µmol g-1 h-1 under the illumination of simulated sunlight with a very good stability.