Ethanol-sensing properties of α-MoO3 nanobelts synthesized by hydrothermal method

Abstract

Orthorhombic molybdenum trioxide nanobelts were successfully synthesized by a facile hydrothermal method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Gas sensing properties of the prepared α-MoO3 nanobelt sensors to ethanol, methanol and acetone vapors were investigated. The α-MoO3 nanobelt sensors show strongest response of 174 for 800 ppm ethanol vapor operating at 300 °C,which is much stronger than the response to methanol and acetone vapor. Generally the response times to ethanol vapor (5-800 ppm) decrease with the increase of operating temperature, from 33 to 61 s at 250 °C to 9–14 s at 400 °C, while the recovery times show a decrease trend with the increase in the concentration of ethanol vapor. The sensing mechanisms responsible for α-MoO3 nanobelt to ethanol vapor are discussed.