In-situ partial cation exchange-derived ZnIn2S4 nanoparticles hybridized 1D MIL-68/In2S3 microtubes for highly efficient visible-light induced photocatalytic H2 production

Herein, a ternary hollow heterostructure (MIL-68/In2S3/ZnIn2S4) has been designed and constructed through two-step in-situ growing procedures including the sulfurization of MIL-68(In) to produce MIL-68(In)/In2S3 (MIS) and partly Zn(II)-exchange of In(III) to produce ternary MIL-68/In2S3/ZnIn2S4 (MISZ). The thus fabricated ternary heterostructure inherit the microtube architecture of MIL-68(In) and the produced ZnIn2S4 (ZIS) nanoparticles were well anchored on MIS microtube. Because of the formation of close adjacent heterojunction, the resulting hierarchical hollow heterostructure MISZ would be beneficial to the visible-light induced photocatalytic hydrogen generation. The relative composition of the ternary components was controlled to find the best photocatalytic activities. Interestingly, being free of cocatalyst and using visible-light irradiation source, the optimized MISZ-15 photocatalyst manifest significant hydrogen evolution rate of 306.0 μmol g−1 h−1, which values are evidently higher than the results by binary MIS and pristine MIL-68(In). By integrating the photo-electrochemical and electron spin resonance (ESR) analyses, a plausible enhanced photocatalytic mechanism has been proposed in detail. Finally, the ternary MISZ heterostructure shows excellent stability and reusability, that provides a new route for constructing other MOF-based functional photocatalysts for efficient H2 production under visible light irradiation.