Construction of a Novel TiO2‐Covalent‐Organic‐Framework Heterojunction for Highly Selective Photo‐Oxidation Coupling of Amines under Visible Light Irradiation

Abstract A novel heterojunction material constructed with titanium dioxide nanoparticles and covalent organic frameworks, TiO 2 @COF‐5 NPs, was designed and synthesized successfully from HHTP, PBBA and TiO 2 under solvothermal conditions. Notably, the TiO 2 @COF‐5 heterojunction demonstrated excellent photocatalytic performance for the aerobic oxidative coupling reaction of benzylamines to N ‐benzyl‐1‐phenyl methanimines under visible light irradiation, and both high conversions (up to 99 %) and high selectivity (99 %) were achieved for various benzylamines. The ameliorated photocatalytic performance might owe much to establishing the systematic coupling between the TiO 2 nanoparticles and covalent organic frameworks, which could effectively extend the wavelength range of visible light absorption and increase more reactive active sites. This study might provide a versatile approach to combining covalent organic frameworks with inorganic semiconductors to give full play to the synergistic effect of catalysis.