Research progress of nonmetallic doped graphite carbon nitride composites in photocatalytic activation of peroxymonosulfate system for organic pollutants removal

Graphite carbon nitride (g-C3N4), as a two-dimensional nonmetallic semiconductor polymer, has been widely used for organic pollutants removal by synergistic photocatalysis-peroxymonosulfate (PMS) oxidation coupling system due to its wide band gap, abundant active sites and low cost. Doping non-metallic elements into g-C3N4 can not only overcome the shortcomings of low visible light utilization efficiency, small specific surface area and rapid recombination of photogenerated electron-hole pairs of pure g-C3N4, and it can also expand visible light response, promote electron migration for PMS activation and improve catalytic activity. In this paper, a comprehensive overview on the preparation methods of non-metallic doped g-C3N4 and their application in the removal of organic pollutants by the synergistic effect of photocatalysis and Fenton-like catalytic/PMS activation reactions. In addition, the photocatalysis-PMS mechanisms of non-metal doped g-C3N4 for pollutant removal are also discussed. Finally, the challenges and opportunities of non-metallic doped g-C3N4 composites in advanced oxidation technology are presented, and this review helps to provide insights into the synergistic effect between non-metallic doped g-C3N4 and photocatalysis-PMS oxidation coupling system in sustainable carbocatalysis.