GAO Liping 1, XU Wenxian 1, WU Leyu 2, SUN kailian 1, HOU Huanhuan 1,3, CHEN Yuping 1
(1. School of Material and Chemical Engineering, Chuzhou University, Chuzhou 239000, Anhui, China; 2. Chuzhou Yinxing New Material Co., Ltd., Chuzhou 239000, Anhui, China; 3. School of Chemistry and Chemical Engineering, Anhui University of Technology, Maanshan 243000, Anhui, China)
Abstract: Toluene is a highly toxic organic substance. In order to detect toluene gas with high sensitivity, monoclinic WO3 nanosheets were synthesized by using a hydrothermal method. The effect of hydrothermal reaction temperature, calcination temperature and the content of citric acid on crystal structure, morphology and toluene gas sensing performance of the WO3 nanosheets were studied and discussed. It is found that with the hydrothermal reaction temperature exhibited a strong influence on phase composition of the WO3 nanomaterials, with the presence of a metastable phase (hexagonal phase). With increasing calcination temperature, the crystallinity is gradually increased, but the lamellar structure is destroyed and the particles are agglomerated. The addition of citric acid has a positive effect on the formation of the lamellar structure. The WO3 nanosheets-based sensor displayed a sensitivity of 9 to 50 ppm toluene at the test temperature of 280 ℃, which is higher than the those to benzene and formaldehyde at the same concentration by two times, demonstrating promising selectivity to toluene.
Key words: WO3 nanosheets; hydrothermal reaction; toluene; gas sensor sensitivity