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

Abstract

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).