Metal-free ultrathin C3N5 photocatalyst coupling sodium percarbonate for efficient sulfamethoxazole degradation

Traditional Fenton reaction takes place at a low pH and generates waste. Additionally, the storage and transportation of liquid H2O2 may pose safety risks. To overcome these disadvantages, an eco-friendly, efficient advanced oxidation process was established with ultrathin-C3N5 photocatalyst coupling sodium percarbonate (SPC). Under visible light irradiation, up to 93.97% of SMZ was removed within 120 min. Such efficient removal was attributed to the high carriers separation efficiency of U-C3N5, which was certified by DFT calculations and characterization methods. All the factors (various anions, pH values, fulvic acid, light sources, and water matrices) had a slight influence on SMZ degradation. Moreover, the toxicities of SMZ and its intermediates were reduced after degradation. Finally, a gelatin aerogel/U-C3N5 composite was obtained to facilitate the recycling of U-C3N5. This work highlights the combination of metal-free photocatalysis with SPC to degrade sulfonamide antibiotics and furthers the development of advanced oxidation process for micropollutant removal.