Influence of Pb and Co-doping on photocatalytic degradation performance of Zno thin films

Nanostructured ZnO thin films with two different dopants namely Pb and Co were prepared by a sol–gel method. The thin films have been prepared from zinc acetate, monoethanolamine and iso-propanol and then they were deposited on glass substrate by using a dip coating method. The structural, morphological, photocatalytic activity and optical absorbance of thin films were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet-visible spectrophotometer and degradation of methylene blue dye (MB). The all thin films exhibited a polycrystalline hexagonal wurtzite structure that revealed by XRD. Due to doping, the average grain size of ZnO thin film increased. All films showed a wrinkle morphology. Photocatalytic activity of thin films was evaluated in aqueous solutions of Methylene Blue (MB) under UV-light illumination. The results indicated that the photocatalytic activity of ZnO thin films increased by Pb doping, conversely Co doping reduced the photocatalytic activity in comparison with the pure ZnO films. Hence speed of degradation of methylene blue by Pb doped ZnO is higher than that of pure and Co doped ZnO.