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 Ce2S3, 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–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 µmol g−1 h−1 under the illumination of simulated sunlight with a very good stability.