Ultraviolet-visible-near-infrared light responsive inorganic/organic S-scheme heterojunctions for efficient H2O2 production

Solar-powered H2O2 synthesis from water and oxygen presents a potential strategy in the industrial and environmental domains. However, insufficient light absorption, poor charge separation efficiency, and the same or nearby catalytic sites for the photocatalysts limit the activity of H2O2 production. Herein, an ultraviolet-visible-near-infrared light responsive S-scheme heterojunction is created by growing ZnIn2S4 (ZIS) subunits firmly on a core of resorcinol-formaldehyde (RF) sphere. The enhanced full-spectrum light response ZIS/RF core-shell structure is evidenced by UV/Vis-NIR diffuse reflectance spectra (DRS). In situ irradiation X-ray photoelectron spectroscopy (XPS) investigation confirms an S-scheme charge transfer mechanism between RF and ZIS. A directional interfacial electric field (IEF) drives the unique spatial separation feature of constructed heterojunction photoexcited carriers and redox centers through the S-scheme transfer pathway with H2O2 production. Under solar light irradiation, the optimized ZIS/RF with core-shell structure shows a robust apparent quantum efficiency (AQY) up to 22.5 % at 420 nm, 1 % at 720 nm, and 0.2 % at 800 nm. With the key reaction intermediates determined by calculating the average number of transferred electrons and oxygen-reactive species, a possible full-spectrum-light-driven redox mechanism of H2O2 synthesis is provided. © 2025