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

Abstract 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.