Construction of a 1D/2D S-Scheme Heterojunction of Mo-Doped WO₃/In-Doped Carbon Nitride for Efficient Hydrogen Peroxide Photosynthesis

Polymeric carbon nitride (CN) is a promising photocatalyst in H2O2 photosynthesis due to its low cost and high 2e(-) oxygen reduction reaction (ORR) selectivity. However, the H2O2 yield is still unsatisfactory due to its limited light absorption and high carrier recombination rate. Herein, an S-scheme heterojunction consisting of Mo-doped WO3 nanowires and In-doped CN nanosheets (Mo-WO3/In-CN) was constructed. The heterojunction exhibits a remarkably enhanced photocatalytic performance with a H2O2 production rate of 3082.9 mu mol g(-1) h(-1), which is 33.4 and 8.6 times those of Mo-WO3 and In-CN, respectively. Moreover, the H2O2 production rate still reaches 462.3 mu mol g(-1) h(-1) in pure water. Mechanism studies demonstrate that H2O2 is produced through dual routes of ORR and water oxidation reaction. The construction of the S-scheme heterojunction enhances the absorption of visible light and improves the separation efficiency and redox ability of the photogenerated carriers. Meanwhile, increased surface area and good hydrophilicity of the heterojunction also contribute to the improved H2O2 yield. This work provides insight into the design of high-efficiency photocatalysts for H2O2 synthesis.