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

Abstract

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.