In-situ construction of ternary Ti₃C₂ MXene@TiO₂/ZnIn₂S₄ composites for highly efficient photocatalytic hydrogen...

Facing the demand of cleaning energy, the development of efficient photocatalysts for hydrogen evolution is a promising way to realize solar-to-chemical energy conversion for solving energy crisis. Hence, a novel hierarchical Ti₃C₂ MXene@TiO₂/ZnIn₂S₄ photocatalyst with rapid charge transfer channels was constructed by two-step hydrothermal for efficient hydrogen production, adopting hydrothermal oxidation to in-situ synthesize Ti₃C₂ MXene embedded with TiO₂ nanosheets (M@TiO₂), which was applied to load ZnIn₂S₄ (ZIS). The hybridized photocatalyst with optimized ZIS amount had a hydrogen generation rate of 1185.8 μmol/g/h, which was higher than that of M@TiO₂ and pure ZIS. That was originated from the outstanding light harvesting of ZIS and Ti₃C₂, sufficient active sites of Ti₃C₂, intimate interfacial contact, and efficient separation and transfer of photogenerated charges via heterojunction. The favorable and rapid charge transfer routes included type-II heterojunction between ZIS and TiO₂ nanosheets, Schottky junction of Ti₃C₂/semiconductor, and metallic Ti₃C₂ with high conductivity. This work revealed the Schottky junction forming between ZIS and Ti₃C₂, and hierarchical M@TiO₂ could be served as advantageous platform and efficient cocatalyst to construct MXene-based photocatalyst.