Enhanced ethanol sensing performance of Cu-doped ZnO nanorods

Abstract

Cu-doped ZnO (Zn1-xCuxO, x = 0.00, 0.01, 0.02, 0.03 and 0.04) nanorods (NRs) were grown on glass substrates by a seed-mediated hydrothermal method for gas sensing applications. The morphological and structural characterizations were performed by x-ray diffraction method (XRD) and scanning electron microscopy equipped with electron dispersive spectroscopy (EDS). Fabricated sensors were tested against H-2, NO2, ethanol, acetone, xylene and toluene at different operation temperatures. It was found that Cu doping enhanced the sensor response of ZnO NRs especially towards ethanol. The highest sensor response against the ethanol were obtained with 2% and 3% Cu-doped ZnO NRs. Moreover, Cu-doping allowed us to operate ZnO NRs sensors at lower temperatures. Although pristine ZnO NRs did not show any sensor response at 100 degrees C, 2% Cu-doped sensors exhibited selective sensor behavior towards ethanol among the other tested gases.