Enhanced Visible-Light-Driven Hydrogen Production through MOF/MOF Heterojunctions

Abstract

A strategy for enhancing the photocatalytic performance of MOF-based systems (MOF: metal-organic framework) is developed through the construction of MOF/MOF heterojunctions. The combination of MIL-167 with MIL-125-NH₂ leads to the formation of MIL-167/MIL-125-NH₂ heterojunctions with improved optoelectronic properties and efficient charge separation. MIL-167/MIL-125-NH₂ outperforms its single components MIL-167 and MIL-125-NH₂, in terms of photocatalytic H₂ production (455 versus 0.8 and 51.2 μmol h^-1 g^-1, respectively), under visible-light irradiation, without the use of any cocatalysts. This is attributed to the appropriate band alignment of these MOFs, the enhanced visible-light absorption, and long charge separation within MIL-167/MIL-125-NH₂. Our findings contribute to the discovery of novel MOF-based photocatalytic systems that can harvest solar energy and exhibit high catalytic activities in the absence of cocatalysts.