Preparation and gas sensing properties of partially broken WO3 nanotubes

• The WO3 sample shows the morphology of nanotubes consisted of the aggregation of many individual nanoparticles.
• The response of WO3 sensor almost linearly increases as the ethanol concentration increases.
• The WO3 sensor reveals ultra-fast response (1 s) and fast recovery time (9–19 s) for ethanol detection.

WO3 nanotubes are fabricated by a facile solvothermal method using WCl6 as the tungsten source. Morphology and structure of the WO3 nanotubes are analyzed by SEM, XRD, XPS and N2 sorption technique. Gas sensing properties of the as-prepared WO3 sensor are systematically investigated by a static gas-sensing system. The results show the triclinic-structure WO3 nanotubes with diameters of about 700 nm are obtained. The sensor based on the WO3 nanotubes reveals ultra-fast response (1 s) and fast recovery time (9–19 s) for ethanol detection. In addition, the WO3 sensor demonstrates high selectivity for ethanol against several gases including methanol, benzene, dichloromethane and hexane. Compared to other WO3 sensors reported in literatures, the WO3 sensor in this work still exhibits a competitive advantage due to unique nanotubular structure. These clearly indicate that WO3 nanotubes are promising sensing materials for ethanol detection.