Tunable charge transfer efficiency in HxMoO3@ZnIn2S4 hierarchical direct Z-scheme heterojunction toward efficient visible-light-driven hydrogen evolution

Hierarchical direct Z-scheme composites of epitaxial ultrathin ZnIn2S4 nanosheets on HxMoO3 nanobelts (HxMoO3@ZnIn2S4) are rationally designed toward effective hydrogen evolution. The quasi-metallic HxMoO3 possesses the high conductivity and the tunable charge transfer efficiency for charge carriers transport. Besides, the hierarchical structure favours the exposure of reactive sites and provide an intimate hetero-interface. [Display omitted] •Hierarchical HxMoO3@ZnIn2S4 composites of epitaxial ultrathin ZnIn2S4 nanosheets on HxMoO3 nanobelts were synthesised.•HxMoO3@ZnIn2S4 heterojunctions act as direct Z-scheme photocatalysts for efficient hydrogen production.•Tunable charge transfer efficiency results from highly conductive HxMoO3 by hydrogen intercalation.•The hierarchical structure increases intimate interface for charge transfer and exposes more reactive sites. A Z-scheme system is ideal for photocatalysis hydrogen evolution due to spatially separating photogenerated electron–hole pairs and strong redox ability. However, the construction of such a system to achieve rapid charge transfer is still a big challenge. Hierarchical functional nanomaterials with controllable morphology, dimensionality, and electronic property can open more possibilities for designing active Z-scheme photocatalysts. Herein, we construct hierarchical direct Z-scheme composites of epitaxial ultrathin ZnIn2S4 nanosheets on HxMoO3 nanobelts, which exhibits 10.5 times higher H2-production activity (5.9 mmol·g−1·h−1) than pristine ZnIn2S4 with visible light. High conductivity and tunable charge transfer efficiency of HxMoO3 component resulting from hydrogen intercalation are favourable to the effective transport of charge carriers. Moreover, hierarchical architecture composed of 2D nanosheets increases intimate interface for effective separation of electron–hole pairs and exposes more reactive sites. The study provides a new sight in designing hierarchical direct Z-scheme photocatalyst for solar fuel generation.