Characterization of undoped and doped CdS nano-thin films by ZnO for photocatalytic application

Abstract

Using Sol-gel technology, nanocomposite CdS: ZnO thin films with an equal molar ratio of 0.5 M on a glass substrate for water decontamination purposes. The ZnO doping ratios were (0, 1, 3, 5) vol. The ultrastructural, morphological, and optical properties of the prepared thin films were studied using X-ray diffraction (XRD), atomic force microscopy (AFM), and UV-vis spectra. The results indicated that the prepared nanostructured CdS: ZnO thin films contain uniformly spaced crystalline grains of both CdS and ZnO. The ZnO-doped selection ratio and uniform grain distribution produced outstanding photocatalytic and photocatalytic performance. With a red shift in the optical band gap of CdS, the UV-Vis transmittance spectrum of the nanocomposite shows behavior that extends almost uniformly throughout the entire UV-visible region according to the near-band edge emissions of CdS and CdS: ZnO, respectively. Last but not least, the photocatalytic activity of the photodegradation of methylene blue dye was investigated and the results indicated an enhanced efficiency of approximately 87% in 60 min, much higher than that of pristine CdS: ZnO as well as CdS.