Constructing creatinine-derived moiety as donor block for carbon nitride photocatalyst with extended absorption and spatial charge separation

Building a donor-acceptor (D–A) type polymeric carbon nitride is a promising way for synthesizing high-performance photocatalysts. Compared with introducing an acceptor unit, incorporating donor blocks can effectively extend the absorption range without altering H2 production sites. Herein, we report a facile method to construct a d-A structure by introducing the creatinine-derived moiety (CDM) into melem networks via copolymerization of creatinine and urea. CDM units arouse a new absorption band at 500 nm and result in the LUMO and HOMO distribute at melem and CDM unit, which promotes the charge spatial separation. The optimal photocatalytic activity of 9454 μmolg−1 h−1 can be achieved. That does not only improve the apparent quantum yield (AQE) at 420 nm from 3.80 % to 8.41 % but also raises the AQE at 500 nm from 0.71 % to 4.57 %. This strategy provides the potential to extend the further visible light response with a decent performance.