Oxygen-vacancy-mediated energy transfer for singlet oxygen generation by diketone-anchored MIL-125

The importance of singlet oxygen ( 1 O 2 ) in synthesis of fine chemicals, inactivation of viruses and bacteria, degradation of pollutants, and photodynamic therapy has promoted the research on photocatalytic generation of 1 O 2 . Metal-organic frameworks (MOFs), owing to the tunable structure, are good candidate photocatalysts for 1 O 2 generation. However, due to the poor visible-light absorption capacity and the invalid recombination of charge carriers, the 1 O 2 generation yields of most MOFs are still limited. Here, we demonstrate that β -diketone anchoring could improve the photocatalytic generation of 1 O 2 by MIL-125 through enhanced energy transfer. The enhanced energy transfer was attributed to both the narrowed bandgap and the diketone-derived oxygen vacancies, which function as the trapping sites for charge carriers. The results here shed light on the generation of 1 O 2 by visible-light-responsive MOFs and provide a new strategy for the design of MOFs-based photocatalysts.