Furan-Based HTCC/In2S3 Heterojunction Achieves Fast Charge Separation To Boost the Photocatalytic Generation of H2O2 in Pure Water

The limitations imposed by the high carrier recombination rate in the current photocatalytic H2O2 production system substantially restrict the rate of H2O2 generation. Herein, we successfully prepared an In2S3/HTCC dense heterojunction bridged by In–S–C bonds through in situ polymerization of glucose on In2S3. This interfacial In–S–C bond provides a fast transfer channel for electrons at the interface to achieve a highly efficient interfacial charge transfer efficiency, leading to the formation of an enhanced built-in electric field between In2S3 and HTCC, thus dramatically accelerating the rate of charge separation and effectively prolonging the lifetime of the photogenerated carriers. Moreover, the coverage of HTCC enhances the absorption of visible light and sorption of O2 by In2S3, while lowering its two-electron oxygen reduction reaction (ORR) energy barrier. Notably, our research demonstrates that In2S3/HTCC can generate H2O2 not only through the well-known two-step one-electron ORR but also via an alternative pathway utilizing 1O2 as an intermediate, thereby enhancing H2O2 production. Benefiting from these advantages, In2S3/HTCC-2 can produce H2O2 at a rate of up to 1392 μmol g–1 h–1 in a pure aqueous system, which is 18.2 and 5.2 times higher than that of pure In2S3 and HTCC, respectively. Our work not only provides a novel synthesis method of new organic/inorganic heterojunction photocatalysts based on HTCC but also offers new insights into the potential mechanism of interfacial bonding of heterostructures to regulate the photocatalytic H2O2 production activity.