Fast charge transfer kinetics in an inorganic–organic S-scheme heterojunction photocatalyst for cooperative hydrogen evolution and furfuryl alcohol upgrading

Abstract

An overall reaction integrating hydrogen (H₂) evolution with organic oxidation achieved by a photocatalytic redox system is highly desirable and still challenging. The emerging step (S)-scheme heterojunction is expected to be a promising strategy to provide photogenerated charges with the highest redox potentials for synchronous H₂ evolution and organic oxidation. Here, an inorganic–organic S-scheme photocatalyst was constructed by in situ growth of Znln₂S₄ nanosheets on Tp-Tta COF nanoplates, forming a unique hierarchical sandwich-like structure. The prepared Znln₂S₄/Tp-Tta COF photocatalyst followed an S-scheme heterojunction mechanism with a strong interfacial internal electric field, 4.15 and 194 times higher than those of pure Znln₂S₄ and the Tp-Tta COF, respectively. Consequently, the optimal photocatalytic simultaneous furfural production and H₂ evolution performance achieved 12.1 and 9.73 mmol g⁻¹ h⁻¹, respectively, with a total quantum yield of 13.91%. This work provides a basis for the rational design of S-scheme photocatalysts to realize the synergetic and efficient utilization of photogenerated electrons and holes.