Gallia-ZnO nanohybrid sensors with dramatically higher sensitivity to ethanol in presence of CO, methane and VOCs

Gallia-ZnO nanohybrid sensors are fabricated and their response to ethanol, CO, methane, acetone and toluene are investigated. Gallia-ZnO samples containing 0-50 wt% Ga2O3 were prepared via a facile coprecipitation method using zinc chloride and gallium nitrate aqueous solutions without any template and calcined at 500 degrees C. The samples were characterized by XRD, EDX, SEM, PL and BET surface area measurement techniques. The samples with up to 5 wt% gallia show hexagonal; wurtzite structure of ZnO, while those containing 10 wt% gallia present additional weak ZnGa2O4 reflexes amplified for the samples with higher gallia contents. The highest responses of 177.3 and 44.3-300 ppm ethanol and CO are observed for the sensors containing 1 and 0 wt% Ga2O3, respectively. The sensor containing 3 wt% Ga2 03-ZnO with a response of 120 is selective to ethanol in presence of CO, acetone, toluene and methane at 300 degrees C. Also, the sensor containing 50 wt% Ga2O3 is selective to ethanol and show negligible responses to 300 ppm of CO, acetone, toluene and 1% methane at the same temperature. (C) 2015 Elsevier B.V. All rights reserved.