Three-component semiconductors just like ZnO-anatase-rutile with different zinc ion content (between 0.1 and 10.0 at%) were prepared by a wet impregnation method and investigated with respect to their behavior in UV photocatalytic oxidation of nitric oxide. The results were correlated with structural, electronic and surface examinations of the catalysts by using X-ray diffraction (XRD) analysis, X-ray photoelectron spectrum (XPS) analysis, transmission electron microscopy (TEM), ultraviolet-visible absorbance spectra (UV-vis) and photoluminescence (PL) spectra. Firstly, it was found that the OH-species were improved on the surface of ZnO-anatase-rutile three-component system, which was favorable for the oxidation of NO by interrupting the formation of adsorbed nitrolysis. Secondly, the lifetime of electrons and holes was prolonged in the ZnO-anatase-rutile three-component system and the enhancement of the photocatalytic activity was observed for the Zn2+ doping concentration ranged from 0.1 to 2.0 at%. (C) 2008 Elsevier B.V. All rights reserved.