CO2-assisted rapid synthesis of porphyrin-based Bi-MOFs for photocatalytic CO2 reduction: An efficient strategy for carbon cycle

Exploring a facile, rapid and efficient route to produce metal-organic frameworks (MOFs) with highly accessible active sites is of great importance for catalysis. Here we demonstrate the CO2 coordination can drive low temperature rapid synthesis of porphyrin-based bismuth-MOFs (Bi-PMOFs) by utilizing synergistic physical and chemical properties of supercritical CO2 (SC-Bi-PMOFs). The molecular-level role of scCO2 in the synthesis of SC-Bi-PMOFs have been investigated through a series of characterizations including in-situ time-dependent infrared spectroscopy, wherein chemical coordination of CO2 promotes to fabricate 2D SC-Bi-PMOFs nanosheets. Moreover, the formation of Cu-PMOFs and Fe-PMOFs proves the universal scCO2 strategy for synthesizing PMOFs. Density functional theory (DFT) calculations together with experiments results confirm the SC-Bi-PMOFs with abundant active sites guarantee efficient ligand-to-metal charge transfer and reduction efficiency of CO2. The high-efficiency utilization of CO2 for synthesizing a series of MOFs and subsequent catalysis on photocatalytic CO2 reduction for valuable chemicals realize the carbon recycle.