Optical, dielectric and photocatalytic properties of ZnO, ZnSe, and ZnO/ZnSe photocatalyst

Methylene blue dye is one of the noxious, carcinogenic, and mutagenic pollutants. Thus, for the sake of a salubrious environment, its treatment through photocatalytic degradation proves to be a crucial remediation technique. Herein, the ZnO/ZnSe nanocomposite, ZnSe, and ZnO photocatalysts are synthesized using an intelligible one-pot solvothermal technique assisted with the treatment of post-annealing. The phase purity, surface morphology, and composition of samples are characterized using analytical techniques. Optical and dielectric characteristics of samples are also investigated. The frequency dependency of dielectric properties are observed to be influenced by average grain size. The as-synthesized catalysts are tested for the methylene blue dye's degradation where ZnO/ZnSe exhibited excellent photocatalytic efficiency of 91.71% in 210 min which is high in comparison to pure ZnSe 86.95%, and pure ZnO 70.71%. The probable reason for this could be enhanced surface area and narrow optical bandgap, high dye adsorbing capacity, and inhibiting the photogenerated electron holes recombination as justified by its BET analysis and optical properties. The persuasive mechanistic elucidation of transfer of charges while utilizing the reactive species is a prominent affirmation of the integrated outcome of nanocomposite catalyst, the sacrificial agent H2O2 under visible light illumination for dye degradation.