BiVO4@ZnIn2S4/Ti3C2 MXene quantum dots assembly all-solid-state direct Z-Scheme photocatalysts for efficient visible-light-driven overall water splitting

Novel BiVO 4 @ZnIn 2 S 4 /Ti 3 C 2 MXene quantum dots (QDs) assembly all-solid-state direct Z-scheme photocatalyst is fabricated via in-situ growth combined with two-step solvothermal strategy, which forms a hierarchical core-shell structure. The proper energy band structure of BiVO 4 and ZnIn 2 S 4 and the formation of a good solid-solid contact interface between them promote the construction of Z-scheme system, which achieves effective charge separation. It is surprisingly discovered that Ti 3 C 2 MXene QDs can be applied as cocatalysts for photocatalytic overall water splitting, which could accelerate the surface redox kinetics of the catalyst due to the unique properties of Ti 3 C 2 MXene QDs . In particular, due to its excellent metal conductivity, a Schottky barrier can be formed at the interface in contact with ZnIn 2 S 4 , further promoting charge separation. BiVO 4 @ZnIn 2 S 4 /Ti 3 C 2 MXene QDs achieves effective visible-light-driven pure water splitting into O 2 and H 2 evolution rates up to 50.83 and 102.67 μmol g −1 h −1 (~1:2). In addition, it also shows high photocatalytic degradation Bisphenol A efficiency of ~96.4 %. The high photocatalytic performance can be ascribed to the all-solid-state direct Z-scheme structure favoring spatial charge separation, Ti 3 C 2 MXene QDs as cocatalysts promoting proton reduction, and hierarchical core-shell structure offering more surface active sites. This work provides new insights to fabricate high-performance direct Z-scheme assembly system.