Spectroscopic and Morpho-Structural Characterization of Copper Indium Disulfide–Zinc Oxide Nanocomposites with Photocatalytic Properties

Abstract

CuInS₂–ZnO nanocomposites were prepared by two combined approaches, namely solvothermal and chemical precipitation. The structure, morphology, composition and optical properties of the nanocomposites was studied by X-ray diffraction (XRD), scanning transmission electron microscopy (STEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and diffuse reflectance spectroscopy (DRS). The influence of ZnO content on the photocatalytic activity of these nanocomposites was studied. The results showed that CuInS₂-ZnO samples possess photocatalytic activity against a Rhodamine B (RhB) synthetic solution. Additionally, electron spin resonance spectroscopy (ESR) coupled with spin trapping technique was used to characterize the reactive oxygen species (ROS). The photocatalytic mechanism was discussed according to ROS generation that were able to degrade the RhB. The photodegradation rate for RhB removal by CuInS₂–ZnO nanoparticles increased with the addition of ZnO nanoparticles on their surface. During the irradiation, both hydroxyl radical (OH⁻) and superoxide anion (O₂⁻) were highlighted suggesting that the CuInS₂–ZnO nanocomposites are suitable for use in water depollution by photocatalysis.

Keywords:

• Copper indium disulfide–zinc oxide nanocomposites
• reactive oxygen species
• X-ray diffraction
• scanning transmission electron microscopy
• Raman spectroscopy

Acknowledgments

The authors would like to express appreciation to the Romanian Ministry of Research, Innovation and Digitization for the financial support through Project PN 19 35 02 03 (Core Program).

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that influenced the work reported in this paper.