Enhanced internal electric field of CdS/NU-M Z-scheme heterojunction for efficient photocatalytic hydrogen evolution

Abstract

Metal-organic frameworks (MOFs) as high-efficiency photocatalysts often face limitations due to the inadequate charge separation and sluggish charge transfer kinetics. Herein, we construct an interfacial linker coordinated heterostructure cadmium sulfide/zirconium-based metal–organic framework (CdS/NU-M) for high-efficiency photocatalytic H2 evolution. The interfacial thiol coordination significantly narrows the energy difference between conduction band of NU-M and valence band of CdS, achieving a Z-scheme charge transfer channel in CdS/NU-M. As a result, a robust internal electric field is found in the formed Z-scheme heterojunction of CdS and NU-M, which is 20 times higher than that of NU-M. Thus, photogenerated charge carries are efficiently separated and transported to the surface, which induces CdS/NU-M with a 10-fold increase of photocatalytic H2 evolution rate over the contrast photocatalyst, up to 84.3 mmol g−1h−1, prominently surpassing most of the reported MOFs and CdS-based photocatalysts. This work highlights the crucial role of interfacial linker coordination in enhancing charge separation and transfer, significantly improving the photocatalytic performance and providing an effective strategy for designing advanced photocatalysts and related technologies.