High molecular oxygen activation capacity of carbon defective g-C₃N₅ for photocatalytic degradation of antibiotics in water

In this study, a carbon deficient g-C₃N₅ for photocatalytic degradation of antibiotics in water was prepared by thermal polymerization at 600 °C followed by hydrothermal at 180 °C for 12 h, and named CN600-12. The variation of XRD patterns in the physical phase characterization combined with calculations for energy bands in density functional theory (DFT) presents a method for analyzing defects in g-C₃N₅. The degradation efficiency of CN600-12 on different antibiotics and dyes reached 90% within 90 min, proving its excellent universal applicability. In addition, the prepared CN600-12 has superior stability and environmental friendliness. The burst experiments and ESR data reflect the high yields of oxygenated reactive groups (·O₂^– and ¹O₂). The oxygen adsorption capacity of the materials was calculated by combining DFT, the effect of defect configuration on oxygen adsorption was analyzed, and photoelectrochemical characterization explored their photogenerated carrier separation ability. The results show that introducing carbon defects improves the adsorption capacity of the material for oxygen. At the same time, improving the energy band structure and the separation of photogenerated carriers give the material a strong activation capacity for molecular oxygen. This study provides a feasible reference for solving the problem of antibiotic pollution in water bodies.