Design of melem-based supramolecular assemblies for the synthesis of polymeric carbon nitrides with enhanced photocatalytic activity

We design a new supramolecular assembly family as reactants to synthesize highly-photoactive porous polymeric carbon nitride (CN), based on a melem-constructed honeycomb, coupled with the insertion of small triazine analogs. The inclusion of small molecules into the melem-based hexameric rings leads to a highly porous CN with controlled electronic, optical, and catalytic properties, as proven by experimental and theoretical studies. The best-performing photocatalyst demonstrates state-of-the-art activity for hydrogen evolution reaction (HER, H2 generation rate of 8075 μmol h-1 g-1), and CO2 reduction (CO2RR, CO production of 1125 μmol g-1 within 3 h) with high quantum yield efficiencies and excellent stability, owing to the enhanced charge separation and light absorption, appropriate energy bands position, and high specific surface area.