Preparation of copper porphyrin photosensitized iron-based MOFs composite photocatalyst and study on CO2 reduction performance

Fe-based MIL-101(Fe) MOFshavea high potential to capture CO2 due to their high porosity, porous structure,and significant interaction with CO2, but the photogenerated electron and hole recombination phenomenon is relatively obvious. Copper tetracarboxyphenyl porphyrin (Cu-TCPP) was incorporated into MIL-101(Fe) as a photosensitive material to forma heterostructure. This enhanced the light absorption capability and the photogenerated electron-hole pairs separation in the composite catalyst. Based on the above factors, the current study reported the synthesis of MIL-101(Fe) by hydrothermal method, and a new composite photocatalyst Cu-TCPP@MIL-101(Fe) was prepared by using Cu-TCPP as a copper source with different mass ratios. Themorphologicaland structural characterizationof the composite catalyst was carried out by XRD, SEM, TEM, BET, and FT-IR, and the CO2 reduction performance of the composite catalyst Cu-TCPP@MIL-101(Fe) was determined by a vacuum CO2 reduction system under simulated sunlight irradiation. The results revealed that MIL-101(Fe) was loaded with Cu-TCPP with the formation of type II heterojunctions that are capable of inhibitingthe electron-hole recombination with improved light absorption capacity, and accelerated reduction rate of CO2. The reduction rateof CO2 into CO was found to be 29 μmol·g−1·h−1.