Fabrication of CuSe/ZnO Heterostructure Photocatalyst for Effective Photocatalytic Degradation of Carcinogenic Dye Pollutants

Abstract

It is essential to remove harmful carcinogenic dyes from the environment because even minute quantities of these contaminants can have a negative influence on ecosystems. One possible method for removing organic and inorganic contaminants from wastewater is heterogeneous photocatalysis. Hence, in this work, we have successfully synthesized CuSe, ZnO, and their heterostructure nanocomposite by utilizing a simple and cost-effective hydrothermal method. A range of characterization techniques, including XRD, XPS, FT-IR, SEM/EDS and UV-Vis spectroscopy analysis were employed to further understand the structure, morphology, composition and optical characteristics of the synthesized samples. The band gap energy for CuSe, ZnO, and CuSe/ZnO samples were obtained to be 2.14, 2.85, and 2.36 eV, respectively. The synthesized nanocomposite was used to test the photocatalytic degradation of two model dye pollutants Crystal violet and Rose bengal as a function of optimized operational parameters viz., dye concentration (15 mg/L for crystal violet and 10 mg/L for rose bengal), catalyst dose (50 mg), illumination time (125 min) and pH (9 for crystal violet and 6 for rose bengal). The findings of this study demonstrated that CuSe/ZnO heterostructure nanocomposite has shown excellent photocatalytic dye degradation performance. At optimized parameters, the degradation efficiency for crystal violet and rose bengal dyes was achieved to be 94.13% and 90.86%, respectively. The photocatalytic degradation rate was favored by pseudo first order Langmuir-Hinshelwood model with rate constants (k) of 0.018 min^− 1 and 0.017 min^− 1 for crystal violet and rose bengal, respectively.

Graphical Abstract