Bifunctional pyridine doping into deficient carbon nitride for efficient NIR hydrogen production and oxygen activation

Low-energy photon conversion is crucial for the efficient utilization of solar energy. To this end, a synergistic chemical structure modification method is practiced to enhance the wide-spectrum photocatalytic activity of g-C 3 N 4 (BPDCN). By altering the calcination time, we achieve an advanced small size morphology state, which significantly improves the photocarrier transport properties of g-C 3 N 4 . Furthermore, the copolymerization reaction, regulated by varying calcination temperatures, synchronously completes the doping of pyridine and the introduction of N-deficient structure in BPDCN. The modified conjugated framework of BPDCN exhibits broad spectral response capability extending up to the near-infrared region. Additionally, the construction of conjugated carbon region enhances the O 2 adsorption property of BPDCN, expanding the advanced oxidation applications in oxytetracycline degradation. The rich-defect structure of BPDCN further boosts the efficient utilization of photogenerated carriers. Consequently, the optimized BPDCN demonstrates an outstanding photocatalytic H 2 evolution (PHE) activity of 4238.1 μmol g⁻¹ h⁻¹ , approximately 63 times higher than that of pristine UCN. BPDCN also shows the significant low-energy photon utilization ability with a measurable PHE activity of 15.7 μmol g⁻¹ h⁻¹ under NIR irradiation. This work highlights the importance of chemical structure design in organic photocatalyst development.