Ethanol sensing properties of CuO nanowires prepared by an oxidation reaction

The ethanol sensing properties of CuO nanowires prepared by oxidation reaction of copper plate have been examined. The characterization of CuO nanowires by FE-SEM, EDS, and TEM revealed diameters of 100–400 nm and a monoclinic structure with a growth direction along 〈1 1 0〉 direction. The ethanol sensing characteristics of CuO nanowires were studied at ethanol concentrations of 100–1000 ppm and working temperatures of 200–280 °C. An increase of resistance was observed under an ethanol vapor atmosphere due to the p-type semi-conducting property of CuO. It was found that the sensitivity, the response and the recovery time depended on the working temperatures and also ethanol concentration. The sensor exhibited the optimum sensitivity of 1.5 to ethanol vapor concentration of 1000 ppm at the working temperature of 240 °C with a response and recovery time of 110 and 120 s, respectively.