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 H-2 production under sunlight. A Type-I to Type-II band alignment transition is demonstrated via introducing an interlayer of Ce2S3, a potential photocatalyst for H-2 evolution, between SnS2 and CeO2. Subsequently, this heterostructure demonstrates tunability in light absorption, charge transfer kinetics, and material stability. The optimized heterostructure (SnS2-Ce2S3-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 mu mol g(-1) h(-1) under the illumination of simulated sunlight with a very good stability.