Facile synthesis of different ZnO nanostructures for detecting sub-ppm NO2 gas

Abstract We present the synthesis of ZnO nanostructures via the solvothermal method with the assistance of ethylene glycol and nickel acetate tetra hydrate, NA. By employing the NA, the synthesized ZnO structures had different morphologies. The synthesized ZnO material was characterized by scanning electron microscopy, x―ray diffraction, Raman spectroscopy, and energy dispersive spectroscopy. The sensitivity to NO2 gas of the synthesized ZnO was investigated using NO2 concentration of 0.25―1.0 ppm at operating temperature of 150―350 °C. The results indicated that the ZnO nanorods could be suitable for NO2 sensors. Based on these findings, we propose fabrication of a sensor detecting NO2 gas at the sub―ppm concentration.