Nitrogen-deficient modified P–Cl co-doped graphitic carbon nitride with enhanced photocatalytic performance

Abstract

Heteroatom doping as an appealing strategy to modulate the electronic structure and enhance the photocatalytic properties of semiconductors. The P and Cl co-doped with nitrogen-deficient graphitic carbon nitride (g-C3N4) was successfully synthesized by the thermal condensation of melamine using ammonium phosphate and ammonium chloride as dopants. The as-prepared P and Cl co-doped g-C3N4 displayed greatly improved visible-light photocatalytic performance, about 5.9 and 2.0 times higher than that of pristine g-C3N4 for the degradation of rhodamine B (RhB) and antibiotic norfloxacin (NOR). The UV–vis absorption spectra and valence band spectra showed that the modified electronic structure of P and Cl co-doped g-C3N4 had a more negative conduction band potential. The ultrathin layered structure of the co-doping sample was formed due to the dynamic gas template by NH4Cl. Moreover, the nitrogen defects were generated in the tri-s-triazine units of g-C3N4, which could provide more active sites and improve the photoexcited charge-carrier separation. According to the scavenging experiment and ESR results, h+ and •O2− species were considered to be critical reactive species for the RhB and NOR degradation. This work provided a facile and efficient way to construct the doping g-C3N4 material with non-metals element and defect structure for environmental decontamination.