Highly selective photoreduction of CO2catalyzed by the encapsulated heterometallic-substituted polyoxometalate into a photo-responsive metal-organic framework

The highly selective photoreduction of CO2into valuable chemical fuels such as CO has been considered as an effective strategy to address modern energy and environmental issues. In this work, we have adopted the well-established impregnation approach to construct a P2W15Ni3{Re(CO)3}3@NU-1000 composite by incorporating heterometallic-substituted P2W15Ni3{Re(CO)3}3polyoxometalate (POM) into the pores of metal-organic framework (NU-1000) host. Upon light irradiation, the resulting P2W15Ni3{Re(CO)3}3@NU-1000 composite can effectively photocatalyze CO2reduction, obtaining a CO production of 28982 μmol g−1with 93.5% selectivity during 10-h photocatalysis. The catalytic system exhibits great long-term recyclability and stability for at least four successive recycles. The proposed photocatalytic mechanism was confirmed by a series of photochemical and spectroscopic analyses.