Self‐Assembly Synthesis of Oxygen and Sulfur Co‐Doped Porous Graphitic Carbon Nitride Nanosheets for Boosting CO2 Photoreduction

Graphitic carbon nitride (CN) has garnered considerable attention in the field of visible-light CO₂ photoreduction, but its efficiency remains limited by the intrinsic π-conjugated skeleton. Here, O and S were co-doped CN (O, S/CN) by a facile "hydrolysis + calcination" approach to modulate the physicochemical and electronic structure. Distinctive from S doped CN (SCN), O, S/CN owned porous layer structure with several nanosheets and less SO₄ ^2- groups on the surface. The amount of heteroatom-doping was achieved by changing the hydrothermal temperature. The optimum O, S/CN-80 achieved moderate CO production rate of 1.29 μmol g^-1 h^-1, which was 3.79 times as much as SCN (0.34 μmol g^-1 h^-1). The O and most S atoms were substitutionally doped and the effect of S doped state on the improved efficiency of CO generation in O, S/CN was also explored based on the theoretical calculations. This work provides an inspiration to develop efficient dual-doped CN photocatalysts for photocatalytic CO₂ reduction.