Ultrathin Sulfur‐Doped g‐C3N4 Nanosheets Controlled by Steam Activation for Enhanced Visible‐Light Photocatalytic Performance

Abstract Graphite carbon nitride (g‐C 3 N 4 ) has garnered considerable attention due to its excellent photocatalytic properties for the degradation of organic matter in wastewater treatment. Herein, sulfur‐doped g‐C 3 N 4 nanosheets (CN−S‐X) were successfully synthesized via physical steam activation using thiourea and urea as precursors. Comprehensive characterizations demonstrate that the enhanced photocatalysis is attributed to the ultrathin structure, highly active site, vacancy defects, and high specific surface area due to the synergy of S doping and steam activation. The as‐prepared CN−S‐25 photocatalyst exhibits a desirable degradation efficiency of 95.4 % for methylene blue dye with a high degradation rate of 2.65×10 −2 min −1 under visible‐light irradiation, which are 2.1 and 5.52 times those for bulk g‐C 3 N 4 , respectively as well as good reusability and stability. This study provides a simple and promising strategy to regulate the nanostructure of g‐C 3 N 4 for highly efficient photocatalytic degradation of organic pollutants.