2% Ce-doped ZnO, prepared by sonochemical wet impregnation method and calcined at 500 degrees C, was characterized by XRD, EDS, XPS, SEM, FT-IR, UV-visible DRS, PL, EIS, and N-2-adsorption and desorption isotherms. Doping reduces the intragranular resistance and recombination of the photogenerated electron-hole pairs. It also shifts the optical absorption edge to visible region. Under UV-A light or natural sunlight (950 +/- 25 W m(-2)), the doped oxide effectively catalyzes the oxidation of cyanide and subsequently the cyanate also. The catalysis follows Langmuir-Hinshelwood kinetics. The solar photocatalysis depends on the area of catalyst bed and the UV photocatalysis enhances with the photon flux. The doped oxide is also an antibacterial agent and its bactericidal efficiency, tested with Escherichia coil in absence of any illumination, is larger than those of undoped oxides. (C) 2010 Elsevier B.V. All rights reserved.