The in situ construction of ZnIn2S4/CdIn2S4 2D/3D nano hetero-structure for an enhanced visible-light-driven hydrogen production

Abstract

By an in situ modification of CdIn₂S₄ nano-octahedron on the surface of ZnIn₂S₄ nanosheets, ZnIn₂S₄/CdIn₂S₄ nano-composites with tight interface contact were obtained by a one-step solvothermal method. Because of the existence of ZnIn₂S₄/CdIn₂S₄ nano-heterostructure, the optimized sample (ZCIS-50) exhibited excellent photocatalytic H₂ generation activity (12.67 mmol h⁻¹ g⁻¹) under visible light, which was approximately 15.1 times that of pure CdIn₂S₄ (0.84 mmol h⁻¹ g⁻¹) and 5.9 times that of ZnIn₂S₄ (2.13 mmol h⁻¹ g⁻¹). Based on experiments and simulation studies, the remarkable improvement of the photocatalytic performance of ZnIn₂S₄/CdIn₂S₄ can be ascribed to the presence of a large number of Cd–S–Zn atomic bridges between ZnIn₂S₄ nanosheets and CdIn₂S₄ nano-octahedrons, which not only promoted the interfacial charge transfer but also inhibited the recombination of light-induced carriers. In Na₂S/Na₂SO₃ solution, the apparent quantum yield of the ZCIS-50 sample at 420 nm was 18.73% with good stability under long-term irradiation. This work emphasizes the key role of interface design and defect engineering of in situ nano heterostructures. It may provide a promising strategy for the progress of high-efficiency photocatalytic water-splitting catalysts.