S-scheme heterojunction of flake-like ZnIn2S4/SrTiO3 nanosheets for improved photocatalytic performance

Abstract

Faced with the dual crises of global energy scarcity and environmental pollution, photocatalytic technology has become a promising solution for synchronous energy conversion and environmental remediation. Herein, we rationally designed a flake-like ZnIn₂S₄/SrTiO₃ (ZIS/STO) S-scheme heterojunction with dual-functional photocatalytic activity, featuring a novel structural-directing template strategy and intimate interfacial contact. Under visible light irradiation, the ZIS/STO composite exhibits superior photocatalytic performance in both H₂ evolution and tetracycline degradation. Its H₂ production rate reaches 1380 μmol h⁻¹ g⁻¹, which is 2.17 times that of pristine ZIS (637 μmol h⁻¹ g⁻¹) and outperforms most reported ZIS-based photocatalysts. For tetracycline degradation, the composite achieves a degradation efficiency of 91.8% within 90 minutes. The enhancement in photocatalytic performance is attributed to the S-scheme charge transfer mechanism, validated by in situ X-ray photoelectron spectroscopy and energy band structure analyses. This work provides critical insights into the application of structural-directing template engineering in the fabrication of high-performance heterojunctions and offers a feasible strategy for designing dual-functional photocatalysts for efficient solar-to-hydrogen conversion and antibiotic degradation.