Condensation of Supramolecular Assemblies at Low Temperatures as a Tool for the Preparation of Photoactive C₃N₃O Materials

We report the synthesis of new photoactive carbon nitride polymers with high oxygen content (CNO) at low calcination temperatures (300–400 °C). To do so, we designed new carbon- and oxygen-rich supramolecular assemblies as reactants. The starting monomers’ composition allows the formation of photoactive CNO semiconductors with extended absorption and ordered morphologies. Interestingly, at these reaction temperatures, the chemical structure of the starting monomers is partially retained, opening a path for the transfer of properties from the molecular level to the final CN materials after condensation. The new CNO polymers exhibit good photoactivity for the hydrogen evolution reaction, CO₂ reduction and rhodamine B dye degradation.