Encapsulating Perovskite Quantum Dots in Iron-Based Metal-Organic Frameworks (MOFs) for Efficient Photocatalytic CO2 Reduction.

Improving the stability of lead halide perovskite quantum dots (QDs) in a system containing water is the key for their practical application in artificial photosynthesis. Herein, we encapsulate low-cost CH3 NH3 PbI3 (MAPbI3 ) perovskite QDs in the pores of earth-abundant Fe-porphyrin based metal organic framework (MOF) PCN-221(Fex ) by a sequential deposition route, to construct a series of composite photocatalysts of MAPbI3 @PCN-221(Fex ) (x=0-1). Protected by the MOF the composite photocatalysts exhibit much improved stability in reaction systems containing water. The close contact of QDs to the Fe catalytic site in the MOF, allows the photogenerated electrons in the QDs to transfer rapidly the Fe catalytic sites to enhance the photocatalytic activity for CO2 reduction. Using water as an electron source, MAPbI3 @PCN-221(Fe0.2 ) exhibits a record-high total yield of 1559 μmol g-1 for photocatalytic CO2 reduction to CO (34 %) and CH4 (66 %), 38 times higher than that of PCN-221(Fe0.2 ) in the absence of perovskite QDs.