Efficient photocatalytic hydrogen peroxide production over S-scheme In₂S₃/molten salt modified C₃N₅ heterojunction

Graphitic phase carbon nitride (g-C₃N₅), as a novel n-type metal-free material, is employed as a visible light-receptive catalyst because of its narrow band gap and abundant nitrogen. To overcome the low carrier mobility efficiency of g-C₃N₅, its modification by K ions was adopted. In addition, In₂S₃ was selected to couple with modified g-C₃N₅ to overcome the recombination of photogenerated e^-/h⁺. As a novel photocatalytic material, it was proven to possess a high visible light absorption capacity and a strong H₂O₂ production ability (up to 3.89 mmol⋅L^-1 in 2 h). Moreover, a S-scheme heterojunction structure was successfully constructed between the two materials, which was tested and confirmed to be successful in raising the photogenerated e^-/h⁺ separation efficiency. Ultimately, the primary processes of photocatalytic H₂O₂ production were summarized by superoxide radical and rotating disc electron measurements. This research provides a fresh perspective for the synthesis of C₃N₅-based S-scheme heterojunction photocatalysts for producing H₂O₂.