Light induced enhancing gas sensitivity of copper-doped zinc oxide at room temperature

Copper-doped zinc oxide (ZnO) (1 mol%) nanocrystals were synthesized using a sol-gel method and characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), inductive coupled plasma with optical emission spectrometry (ICP-OES). The XRD result indicated that the introduction of copper had no influence on the crystal structure of ZnO, though ICP-OES exhibited the molar ratio of copper and zinc was 0.86:100. The gas response of the copper-doped ZnO was also studied to ethanol and acetone without and with the illumination of 355 nm light. It was found that the ultraviolet light irradiation could enhance the gas response, and the mechanism with irradiation was discussed. Our results demonstrated that light irradiation was a promising approach to achieve large response at room temperature. (c) 2008 Elsevier B.V. All rights reserved.