Construction of 3D hierarchical microarchitectures of Z-scheme UiO-66-(COOH)2/ZnIn2S4 hybrid decorated with non-noble MoS2 cocatalyst: A highly efficient photocatalyst for hydrogen evolution and Cr(VI) reduction

To solve the problem of energy shortage and environmental pollution, the construction of properly designed photocatalysts is a promising method. Here, UiO-66-(COOH) 2 /ZnIn 2 S 4 Z-scheme photocatalyst decorated with MoS 2 nanosheets was designed and constructed as a novel 3D hierarchical structure via hydrothermal methods. In this particular 3D hierarchical structure, the UiO-66-(COOH) 2 nanoparticles are decorated in the interweaving petal nanosheets of ZnIn 2 S 4 microspheres, while the co-catalyst of MoS 2 is folded at the edge of these interweaving petals. The excellent heterojunctions with highly exposed catalytic active sites are correspondingly built, and the close interfacial interaction between UiO-66-(COOH) 2 , MoS 2 and ZnIn 2 S 4 create a stage for fast transfer of photogenerated electrons, which are both effective for the photocatalytic reaction process. Also, the Z-scheme charge-transfer process improves the oxidizability and reducibility between UiO-66-(COOH) 2 and ZnIn 2 S 4 . As a result, the optimized UiO-66-(COOH) 2 /MoS 2 /ZnIn 2 S 4 photocatalyst exhibits excellent photocatalytic hydrogen production (18.794 mmol h −1  g −1 ) and reduction of Cr(VI) (0.06850 min −1 ) under simulated solar light irradiation, which are 15.3 and 6.7 times higher than that of bare ZnIn 2 S 4 , respectively, and also the prominent stability and excellent recyclability are obtained. This study provides new insights into the research on the Z-scheme system containing MOF components for growing energy and environmental demands.