Major issues in photocatalysis include improving charge carrier separation efficiency at the interface of semiconductor photocatalysts and rationally developing efficient hierarchical heterostructures. Surface continuous growth deposition is used to make hollow Cu 2-x S nanoboxes, and then simple hydrothermal reaction is used to make core-shell Cu 2-x S@ZnIn 2 S 4 S-scheme heterojunctions. The photothermal and photocatalytic performance of Cu 2-x S@ZnIn 2 S 4 is improved. In an experimental hydrogen production test, the Cu 2-x S@ZnIn 2 S 4 photocatalyst produces 4653.43 µmol h −1 g −1 of hydrogen, which is 137.6 and 13.8 times higher than pure Cu 2-x S and ZnIn 2 S 4 , respectively. Furthermore, the photocatalyst exhibits a high tetracycline degradation efficiency in the water of up to 98.8%. For photocatalytic reactions, the hollow core-shell configuration gives a large specific surface area and more reactive sites. The photocatalytic response range is broadened, infrared light absorption enhanced, the photothermal effect is outstanding, and the photocatalytic process is promoted. Meanwhile, characterizations, degradation studies, active species trapping investigations, energy band structure analysis, and theoretical calculations all reveal that the S-scheme heterojunction can efficiently increase photogenerated carrier separation. This research opens up new possibilities for future S-scheme heterojunction catalyst design and development.
Shanhao He,Dongmei Yang,Zuqi Li,Bin Li,Huiyan Pan,Zhiqiang Wang,Keliang Wu,Zhiyong Liu
To address the challenges of insufficient near-infrared light utilization and rapid charge recombination in traditional photocatalysts, this study designed and synthesized a hollow-structured Cu 2−x S@ZnIn 2 S 4 S-scheme heterojunction with synergistic photothermal-photocatalytic properties. The synergistic mechanism between plasmonic photothermal effects and heterojunction charge-transfer in broad-spectrum catalysis was systematically elucidated. Experimental results demonstrated that the composite achieved a hydrogen evolution rate of 32.58 mmol g −1 h −1 under AM 1.5G irradiation without cooling water (WCW), which is 3.00 times that of pure ZnIn 2 S 4 . Moreover, the solution temperature reached 47.4 °C under near-infrared (NIR) illumination. Theoretical analysis revealed that the localized surface plasmon resonance (LSPR) of Cu 2−x S extended light absorption into the NIR region and generated a photothermal effect. Meanwhile, the S-scheme band alignment, together with multiple light scattering induced by the hollow structure, synergistically optimized carrier separation and promoted directional charge migration. The catalyst exhibited excellent stability over 750 min and demonstrated measurable NIR-driven activity at wavelengths above 800 nm. By coupling band-engineering with photothermal conversion, this work provided a theoretical foundation and a material prototype for designing efficient full-spectrum solar-to‑hydrogen conversion systems, showing clear application potential in photothermal-assisted artificial photosynthesis.