Optical properties and photocatalytic activity of Nd-doped ZnO powders

To improve the photocatalytic activity of zinc oxides, ZnO powders doped with different neodymium (Nd) concentrations were prepared via hydrothermal method. X-ray diffraction (XRD) together with X-ray photoelectron spectroscopy (XPS) patterns revealed that Nd atoms were successfully incorporated into the ZnO lattice. XRD pattern also showed some anisotropy of the powders. The photoluminescence (PL) spectrum demonstrated a strong and broad peak in the visible light region, and the intensity of visible light emission was enhanced by Nd-doping. The photocatalytic activity was evaluated by the degradation of methyl orange solution. It is shown that doping of Nd into ZnO induces an increase of the photocatalytic activity and it attains to optimum at 3% (mole fraction) doping concentration. The intense visible light emission and the enhanced photocatalytic activity were explained by the increase in electron hole pairs and induced defects like antisite oxygen OZn and interstitial oxygen Oi, due to the doping of Nd.