Multi-mode photocatalytic performances of CdS QDs modified CdIn₂S₄/CdWO₄ nanocomposites with high electron transfer ability

In general, quantum dots have the property of generating a plurality of charge carriers using hot electrons or using a single high-energy photon to improve the photocatalytic properties of the material. In this paper, CdS QDs@CdIn₂S₄/CdWO₄ modified by CdS QDs was synthesized by the microwave-assisted hydrothermal method, and its composition, crystal structure, morphology, and surface physicochemical properties were well characterized. Electron microscopy results showed that CdS QDs@CdIn₂S₄/CdWO₄ composite material exhibited a sheet structure with a length of ca. 350 nm and a width of ca. 50 nm, and CdS QDs uniformly distributes with a diameter of about 5 nm on the sheet structure. UV-visible diffuse reflectance tests showed that the combination of CdS QDs and CdIn₂S₄ can extend the light absorption range of CdWO₄ to the visible region. Photoluminescence spectroscopy confirmed that CdS QDs had efficient electron transport capabilities. The multi-mode photocatalytic activity of CdS QDs@CdIn₂S₄/CdWO₄ showed an excellent ability to degrade organic pollutants. Under the conditions of no co-catalyst and Na₂S-Na₂SO₃ as the sacrificial agent, the hydrogen production of CdS QDs@CdIn₂S₄/CdWO₄ can reach 221.3 μmol g⁻¹ when exposed to visible light (λ > 420 nm) for 8 h.

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