Effect of Fe and Co doping on ethanol sensing property of powder-based ZnO nanostructures prepared by sol–gel method

Iron and cobalt doped zinc oxide were prepared by the sol–gel method. The doping concentration was varied between 5 and 10 wt.%. Structural and morphological features of the samples were investigated comparatively by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FTIR). They were also placed in an electric circuit and their sensing characteristics toward ethanol vapors were studied. It was found that, the gas response was impressed by doping. The optimal operating temperature, dynamic response, sensitivity and response and recovery times of the samples have been measured. The operating temperature and the time of response and recovery of the sensor were generally reduced after doping. According to our results, by considering the time of rising/ falling, the doped samples have a relatively better status than pure zinc oxide sample and in particular, the sample with 10% cobalt doped (ZC10) had a competitive attitude compared to pure zinc oxide due to significant reduction in response/recovery times.