Cu-doped ZnO nanorods based QCM sensor for hazardous gases

Cu doped ZnO nanorods (NRs) were deposited on quartz crystal microbalance (QCM) oscillators to detect hazardous gases at room temperature. Cu doped and pristine ZnO NRs have been successfully synthesized by a two-step electrochemical deposition technique. Electrodeposition conditions were optimized to get highly ordered ZnO NRs. Fabricated sensors were tested against isopropyl alcohol, dichlorobenzene, ethyl acetate, toluene, xylene, H2S, HCN and NO2. The results indicated that Cu doping advances sensor response of ZnO NRs especially for H2S and HCN. 1% Cu doped ZnO NRs sensor showed the highest sensor response. Doping concentration dependent increment in sensor response was explained with the enhancement of physisorption properties of the NRs surface. Among the tested gases, the response values for H2S and HCN at room temperature were measured as similar to 68 at 6.6 ppm and similar to 57 at 8.8 ppm, respectively. The limit of detection values of 1% Cu doped ZnO NRs sensor were calculated as 79 and 169 ppb for H2S and HCN, respectively. (C) 2020 Elsevier B.V. All rights reserved.