Microwave-assisted synthesis of edge-grafted carbon nitride by triazole rings for efficient photocatalytic hydrogen evolution

Copolymerization of conjugated nitrogen heterocycles within carbon nitride nowadays is proven to be a successful strategy to promote charge separation. Here, a novel edge-grafted carbon nitride nanosheets by triazole rings were synthesized from the copolymerization of dicyandiamide and 3-amino-1, 2, 4-triazole via microwave-assisted heating with improved yield. Based on the building of a feasible donor-acceptor (D-A) system by such edge grafting, the rapid charge transfer pathways were formed. Benefiting from the thin-layer structure of carbon nitride via microwave-assisted heating and abundant π electrons by intramolecular doping, the system showed enhanced visible light absorption from n-π∗ electrons transition, facile charge separation and transfer, and then an increased H2 evolution rate (637.58 μmol h−1 g−1), which is 17.43 times than the triazole modified sample from conventional thermal condensation method. This work enlightens an innovative pathway for the regulation of carbon nitride photocatalysts by conjugated nitrogen heterocycles for efficient solar energy conversion applications.