One-step preparation of sulfur-doped porous g-C₃N₄ for enhanced visible light photocatalytic performance

Nonmetal doping is a convenient method to adjust the visible light photocatalytic activity of graphitic carbon nitride (g-C3N4). Herein, highly active sulfur-doped porous g-C3N4 (C3N4-S) was successfully prepared by one-step calcination using thiourea and melamine as the precursors. C3N4-S exhibited excellent photocatalytic performance for the degradation of Rhodamine B (RhB) under visible light irradiation. C3N4-S not only promoted the separation of photogenerated electron-hole pairs, but also enhanced electron transfer, resulting in a great improvement in the photocatalytic efficiency. Based on capture experiments and DMPO spin-trapping ESR spectra, the superoxide radical (˙O2-) was proved to be the predominant active species and the possible photocatalytic mechanism of C3N4-S was proposed. The photocatalytic mechanism of RhB degradation over C3N4-S was further explored using high-resolution mass spectra (HRMS).