Preparation and Gas Sensing Properties of Hierarchical Flower-Shaped Bi2WO6

Abstract

Hierarchical flower-shaped Bi2WO6 was obtained by a simple hydrothermal method. Morphology and structure of the Bi2WO6 were characterised by single electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and N2 adsorption techniques. Gas sensing properties of the Bi2WO6 sensor were investigated by a static gas-sensing system. The results show the as-synthesised flower-shaped product is pure orthorhombic Bi2WO6, which is composed of nanosheets with ~10–20 nm in thickness and hundreds of nanometres in planar size. At this optimal operating temperature of 300°C, the Bi2WO6 sensor exhibits ultra-fast response (1-2 s) and fast recovery time (6–12 s) towards ethanol detection, and high selectivity to other gases such as methanol, benzene, dichloromethane, and hexane.