Enhanced Photocatalytic CO2 Reduction by Novel Designed Porphyrin-Based MOFs: From Accurate QSPR Model to Experimental Exploration

A reliable quantitative structure-property relationship (QSPR) model was established for predicting the evolution rate of CO2 photoreduction over porphyrin-based metal-organic frameworks (MOFs) as photocatalysts. The determination coefficient (R2) for both training and test sets was 0.999. The root-mean-squared error of prediction (RMSEP) obtained was 0.006 and 0.005 for training and test sets, respectively. Based on the proposed model, two porphyrin-based MOFs, Cu-PMOF and Co-PMOF, were designed, synthesized, and applied for CO2 photoreduction under UV-visible irradiation without any additional photosensitizer. The X-ray diffraction (XRD), diffuse reflectance spectroscopy (DRS), and Fourier transform infrared (FTIR) measurements revealed the successful formation of the porous MOFs. The N2 adsorption isotherms at 77 K showed a high Brunauer-Emmett-Teller (BET) surface area of 932.64 and 974.06 m2·g-1 for Cu-PMOF and Co-PMOF, respectively. Theoretical and experimental results showed that HCOOH evolution rates over Cu-PMOF and Co-PMOF were (127.80, 101.62 μmol) and (130.6, 103.47 μmol), respectively. These results were robust and satisfactory.