2D-MOF/2D-MOF heterojunctions with strong hetero-interface interaction for enhanced photocatalytic hydrogen evolution

Metal organic framework (MOF) shows great potential in the research field of photocatalysis, and it is a big challenge to achieve efficient photocatalytic activity. In this work, we have successfully grown two-dimensional MOF (2D-MOF) nanosheets on 2D-MOF nanosheets for the first time using a homometallic nodal strategy, and successfully prepared ultrathin nanosheets with tightly bound 2D/2D heterojunctions. 2D Ni-BDC nanosheets were used as carriers to grow 2D Ni-TCPP nanosheets on top of them. Ni-TCPP has a high light absorption capacity, thus extending the light absorption range of 2D/2D heterojunctions. The tight coupling of the heterojunction effectively shortens the electron transfer distance, promotes the separation of interfacial charges, and improves the photocatalytic activity. Particularly, Ni-BDC/Ni-TCPP-3 can achieve to a hydrogen production rate of 428.0 μmol·g −1 , approximately 5.75 times higher than Ni-BDC and 5.24 times higher than Ni-TCPP, respectively. Thus, 2D-MOF/2D-MOF heterojunctions provide a promising strategy for enhancing photocatalytic performance through rational heterostructure design with homometallic node strategy. Graphical abstract