Edge functionalized with benzenesulfonyl groups of g-C3N4 nanosheets as a highly efficient photocatalyst for water purification

Photocatalytic water purification is a promising method for environmental remediation, but it is greatly hindered by the rapid charge carrier recombination behavior of the photocatalysts. Herein, a simple wet-chemical method is developed for grafting electron-withdrawing benzenesulfonyl groups at the edges of g-C₃N₄ nanosheets. These exhibited a superior and versatile photocatalytic performance on the degradation of organic contaminant, as well as disinfected Escherichia coli (E. coli) bacteria under visible light illumination. Systematic studies reveal that the grafting of benzenesulfonyl groups led to the synergic effect in ultrathin g-C₃N₄ nanosheets of enhancing the photogenerated charge carrier separation on surface, improving light absorption, changing electronic band structure, and causing surface charge redistribution, all of which are beneficial for enhancing the photocatalytic performance. Notably, these edge-activated g-C₃N₄ photocatalysts also demonstrate remarkable photocatalytic activity in the real tap water and urban wastewater, indicating their promising potential for application in real wastewater treatment.