Fabrication of porous Cd-doped ZnO nanorods with enhanced photocatalytic activity and stability

Abstract

Porous Cd-doped ZnO nanorods have been successfully synthesized on a large scale by a precursor thermal decomposition route. Rod-like Zn1−xCdxC2O4 precursors with 1 μm in average length were firstly fabricated via a solvothermal process. After calcining the Zn1−xCdxC2O4 precursors, the porous Cd-doped ZnO nanorods were obtained. The as-prepared samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), ultraviolet-visible (UV-vis) diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity of the as-prepared Cd-doped ZnO nanorods for degradation of organic compounds and the printing and dyeing sewage under the 365 nm of UV light illumination were investigated. The results show that Cd-doped ZnO nanorods have a higher photocatalytic activity than pure ZnO and P25. This enhanced photocatalytic activity is attributed to the Cd doping, which increases the defects in the ZnO nanoparticles and reduces the bandgap width of ZnO. Furthermore, the photodegradation rate does not show an obvious decrease during ten successive cycles, indicating that our Cd-doped ZnO nanorods are very stable.