Highly crystalline sulfur and oxygen co-doped g-C3N4 nanosheets as an advanced photocatalyst for efficient hydrogen generation

Abstract

Heteroatom doping has become a promising strategy to tailor the band structure and physicochemical properties of graphitic carbon nitride (g-C₃N₄). However, doping heteroatoms usually leads to decreased crystallinity, and thereby inferior photocatalytic performance. Herein, highly crystalline S and O co-doped g-C₃N₄ nanosheets (SOCNSs) have been successfully prepared for the first time by a simple two-step annealing process with melamine as the g-C₃N₄ precursor and taurine as the S and O doping source. Owing to the enhanced visible light absorption, high crystallinity and the abundant surface active sites, the resultant SOCNSs demonstrate drastically enhanced transport and separation efficiency for photogenerated charges. As a result, under visible light irradiation, SOCNSs show a stable H₂ production rate of 251 μmol h⁻¹ and a brilliant AQE of 23.75% at 420 nm. Our study demonstrates a simple and efficient way for co-doping heteroatoms into g-C₃N₄, enabling a new avenue for efficient photocatalytic hydrogen production.