Enhancing Photocatalytic CO₂RR by Modulating the Active Sites of COF-Based Catalysts

The catalytic conversion of CO₂ into valuable chemicals using metalized covalent organic frameworks (COFs) as catalysts is a promising method for reducing atmospheric CO₂ levels. Herein, a aldehyde-amine COF (TAPT-Tp) at room temperature and pressure and their metallized results is synthesized, Ni-TAPT-Tp and Ti-TAPT-Tp. The photocatalytic results indicate that the CO₂ to CO reduction rate is 6182.5 µmol g^-1 h^-1 for Ni-TAPT-Tp, but only 1615.4 µmol g^-1 h^-1 for Ti-TAPT-Tp. Density functional theory (DFT) simulations further demonstrate that for intermediates ^*CO₂, ^*COOH, and ^*CO, the energy of Ni-TAPT-Tp is consistently lower than that of Ti-TAPT-Tp, indicating that Ni-TAPT-Tp exhibits superior photocatalytic performance for CO₂RR. This work provides a reference for optimizing the coordination structure of M-COFs to obtain highly active and selective CO₂RR.