WO3 nanocrystals: Synthesis and application in highly sensitive detection of acetone

Abstract: WO3 nanocrystals have been prepared by a sol–gel route and characterized by X-ray diffractometry, scanning electron microscopy, and transmission electron microscopy. The experimental results show that WO3 nanocrystals have a high crystallographic quality and a good dispersivity. The particles’ sizes are in the range of 25–100nm. The fabricated WO3 nanocrystal-based sensors have an excellent sensitivity and selectivity to acetone, and display a rapid response and recovery characteristics. The developed sensors exhibit a detection limit down to 0.05ppm at 300°C, rendering a promising application in noninvasive diagnosis of diabetes. The response mechanism of the WO3 nanocrystal sensor to low concentration of acetone has been discussed based on the depletion layer model. [Copyright &y& Elsevier]