Preparation and Gas-sensing Properties of Cu2+-doped ZnO Nanorods

Cu2+-doped ZnO nano-rod powders (0–6mol%) were prepared via solvothermal method. The crystal and micro-morphology of the doped ZnO nano-rods were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The effects of Cu2+ dopant and the thermal condition (reaction temperature and duration) on the gas sensitivities of ZnO nano-rods were studied. The gas sensing properties of pure ZnO nanorod sensor and 3mol% Cu2+-doped ZnO nano-rod sensors to formaldehyde, acetic acid, toluene, ethanol, acetone and trimethylamine were also studied. The results show that the micro-morphology of ZnO powders are nano-rods, the lengths and diameters of ZnO nanorods change with the variation of the Cu2+ concentration. The sensor based on 3mol% Cu2+-doped ZnO nano-rods exhibits high response and good selectivity to dilute ethanol, the responses to 1×10-3 ethanol and 1×10–6 ethanol reach 380.5 and 4.2 when it works at 395 respectively, and its response time and recovery time are 16 s and 40 s, respectively.