Synergistic interfacial engineering of a S-scheme ZnO/In2S3 photocatalyst with S−O covalent bonds: A dual-functional advancement for tetracycline hydrochloride degradation and H2 evolution

Efficient interfacial charge transfer and robust interface interactions are crucial to achieve superior spatial separation of carriers and develop advanced heterogeneous photocatalysts. This study describes the synthesis of a novel S-scheme heterojunction of ZnO/In2S3, with S−O covalent bonds, achieved through a hydrothermal method. The optimized heterojunction shows exceptional photocatalytic activity, achieving a H2 generation rate of 2488 μmol g-1 h-1 and a degradation efficiency of 86% for tetracycline hydrochloride (TCH) within 2 hours. These values surpass those of In2S3 alone by 35 and 1.4 times, respectively. Various techniques, including electron spin resonance, X-ray photoelectron spectroscopy, Kelvin probe force microscopy and density functional theory calculations confirm the S-scheme heterojunction. The establishment of a chemical S−O bond between In2S3 and ZnO facilitates an atomic level interfacial pathway, enabling efficient transportation of interfacial electrons.