Zinc oxide obtained by the solvothermal method with high sensitivity and selectivity to nitrogen dioxide

The effect of heat treatment using [Zn(H2O)(O2C5H7)2] precursor ethylene glycol solution (synthesis temperature 125–185 °C, holding time 2–6 h) on the characteristics of the obtained nanocrystalline zinc oxide powder was studied. Under all synthesis conditions crystalline ZnO was formed with a wurtzite structure and an average crystallite size of 8–37 nm. The thermal behaviour and microstructure of the nanostructured ZnO powder were studied. The sensory properties of the obtained films in terms of the detection of hydrogen, methane, carbon monoxide and nitrogen dioxide were studied. The high sensitivity and selectivity of a thick ZnO film (synthesis temperature 145°С, holding time 6 h) when detecting NO2 was established. It was found, that humidity had almost no effect on response value for NO2 detection.