3D ordered macroporous sulfur-doped g-C3N4/TiO2 S-scheme photocatalysts for efficient H2O2 production in pure water

Photocatalytic hydrogen peroxide (H2O2) production offers a clean and cost-efficient alternative to the traditional anthraquinone oxidation approach. Herein, a step-scheme (S-scheme) heterojunction photocatalyst is fabricated by coupling TiO2 with three dimensionally ordered macroporous sulfur-doped graphitic carbon nitride (3DOM SCN/T) by electrostatic self-assembly. The optimized photocatalyst achieved a high photocatalytic H2O2 production activity with a yield of 2128 μmol h−1g−1 without the addition of hole scavengers. The remarkable performance was attributed to the synergy between the 3DOM framework and the S-scheme heterojunction. The former enhances light harvesting and provides abundant active sites for surface reactions, while the latter promotes the spatial separation of photogenerated carriers and enhances the redox power. Finally, the mechanism of photocatalytic H2O2 production over the 3DOM SCN/T S-scheme composite is proposed. This work provides novel insights into the development of efficient photocatalysts for H2O2 production from water and O2.