Bottom-up strategy for precisely designing and fabricating direct Z-scheme photocatalyst with wedge-type heterointerface bridged by chemical bond

[Display omitted] •MoSe2-WSe2@Sv-ZnIn2S4 Z-scheme photocatalyst was designed via a bottom-up strategy.•The surface concave pits served as arching sites for the wedging of MoSe2 and WSe2.•Wedge-type heterointerface with Mo-S and W-S provided charge transfer channels.•Internal electric field donated Z-scheme charge transfer driving force.•MoSe2-WSe2@Sv-ZnIn2S4 photocatalyst presented ultrahigh H2 evolution activity. It is still a big challenge to realize the bottom-up design and fabrication of high-efficient photocatalyst. Herein, MoSe2-WSe2@Sv-ZnIn2S4 (MoSe2-WSe2@Sv-ZIS) Z-scheme photocatalyst with chemical bond bridged wedge-type heterointerface is designed and synthesized based on a bottom-up strategy from band matching and surface modulating to wedge-type heterointerface constructing. Experimental and characterizations results reveal the basic principle for the enhanced photocatalytic activity, in which the internal electric field provides charge transfer driving force, the chemical bond connected wedge-type heterointerface with ample atomic-level charge transfer channels promotes interfacial photocarriers transfer, and the S-vacancies accelerates photocarriers separation. As a result, MoSe2-WSe2@Sv-ZIS achieves a H2 evolution rate of 120.74 mmol·g−1·h−1 (with sacrificial agent) and 2.27 mmol·g−1·h−1 (without sacrificial agent), an apparent quantum efficiency of 16.3% at 420 nm, and nearly 90% of H2 production retention after 10 times successive uses. This work donates a design model on fabricating high-performance photocatalyst with chemical bond bridged allotypic heterointerface.