“All-in-one” covalent organic framework for photocatalytic CO2 reduction

Constructed by selecting appropriate building blocks, covalent organic frameworks (COFs) can be endowed with a variety of specific functions. Herein, we successfully synthesized an imine-linked H2PReBpy-COF with the CO2 reduction catalyst [ReI(bpy)(CO)3Cl] and the porphyrin photosensitizer as the monomeric building units. The light-harvesting properties of the porphyrin itself, augmented by the extended π-conjugated planar structure of 2D COF, enable H2PReBpy-COF the excellent light-harvesting capability, efficient charge separation, and fast interfacial charge transfer. In addition, a large amount of uniformly distributed [ReI(bpy)(CO)3Cl] units offer H2PReBpy-COF an excellent activity toward photocatalytic CO2 reduction with moderate selectivity and reusability. This study demonstrated a proof of concept in which the advantages of COFs and functional monomers are rationally integrated for photocatalytic solar fuel conversion.