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 co-precipitation method using zinc chloride and gallium nitrate aqueous solutions without any template and calcined at 500 °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% Ga2O3-ZnO with a response of 120 is selective to ethanol in presence of CO, acetone, toluene and methane at 300 °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.