Furan-Based HTCC/In<sub>2</sub>S<sub>3</sub> Heterojunction\nAchieves Fast Charge Separation To Boost the Photocatalytic Generation\nof H<sub>2</sub>O<sub>2</sub> in Pure Water

The\nlimitations imposed by the high carrier recombination rate\nin the current photocatalytic H<sub>2</sub>O<sub>2</sub> production\nsystem substantially restrict the rate of H<sub>2</sub>O<sub>2</sub> generation. Herein, we successfully prepared an In<sub>2</sub>S<sub>3</sub>/HTCC dense heterojunction bridged by In–S–C\nbonds through in situ polymerization of glucose on In<sub>2</sub>S<sub>3</sub>. This interfacial In–S–C bond provides a fast\ntransfer channel for electrons at the interface to achieve a highly\nefficient interfacial charge transfer efficiency, leading to the formation\nof an enhanced built-in electric field between In<sub>2</sub>S<sub>3</sub> and HTCC, thus dramatically accelerating the rate of charge\nseparation and effectively prolonging the lifetime of the photogenerated\ncarriers. Moreover, the coverage of HTCC enhances the absorption of\nvisible light and sorption of O<sub>2</sub> by In<sub>2</sub>S<sub>3</sub>, while lowering its two-electron oxygen reduction reaction\n(ORR) energy barrier. Notably, our research demonstrates that In<sub>2</sub>S<sub>3</sub>/HTCC can generate H<sub>2</sub>O<sub>2</sub> not only through the well-known two-step one-electron ORR but also\nvia an alternative pathway utilizing <sup>1</sup>O<sub>2</sub> as\nan intermediate, thereby enhancing H<sub>2</sub>O<sub>2</sub> production.\nBenefiting from these advantages, In<sub>2</sub>S<sub>3</sub>/HTCC-2\ncan produce H<sub>2</sub>O<sub>2</sub> at a rate of up to 1392 μmol\ng<sup>–1</sup> h<sup>–1</sup> in a pure aqueous system,\nwhich is 18.2 and 5.2 times higher than that of pure In<sub>2</sub>S<sub>3</sub> and HTCC, respectively. Our work not only provides\na novel synthesis method of new organic/inorganic heterojunction photocatalysts\nbased on HTCC but also offers new insights into the potential mechanism\nof interfacial bonding of heterostructures to regulate the photocatalytic\nH<sub>2</sub>O<sub>2</sub> production activity.