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 H 2 O 2 production system substantially restrict the rate of H 2 O 2 generation. Herein, we successfully prepared an In 2 S 3 /HTCC dense heterojunction bridged by In−S−C bonds through in situ polymerization of glucose on In 2 S 3 . 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 In 2 S 3 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 O 2 by In 2 S 3 , while lowering its two-electron oxygen reduction reaction (ORR) energy barrier. Notably, our research demonstrates that In 2 S 3 /HTCC can generate H 2 O 2 not only through the well-known two-step oneelectron ORR but also via an alternative pathway utilizing 1 O 2 as an intermediate, thereby enhancing H 2 O 2 production. Benefiting from these advantages, In 2 S 3 /HTCC-2 can produce H 2 O 2 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 In 2 S 3 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 H 2 O 2 production activity.