Tailoring photoactivity of polymeric carbon nitride via donor-π-acceptor network

Molecular doping approach can effectively modulate the charge transfer kinetics of polymeric carbon nitride (PCN) photocatalyst. Herein, we show that doping of PCN with a strong electron-withdrawing 2,3-diaminopyridine (DAP) induces the formation of donor-π-acceptor (D-π-A) network. As formed D-π-A type network demonstrated a photocatalytic hydrogen production activity of 6.56 mmolg−1 h−1, which is 4.5-times greater than the pure PCN. The optoelectronic features characterized by spectroscopic techniques indicate rapid separation of photoexcited charge carriers and extended light-harvesting ability of DAP-doped PCN. Further, the theoretical analysis revealed that DAP-doped PCN has near-ideal hydrogen adsorption free energy of − 0.11 eV, which supports the excellent hydrogen production performance. Importantly, the hydrogen production activity demonstrated here outperforms several state-of-art molecular-doped PCN-based catalysts. This study sheds light on the effective production of PCN-based D-π-A networks using conjugated heterocyclic compounds.