Nano-crystalline tungsten oxide NO2 sensor

2019-07-18 09:07:14

The sensor tungsten oxide NO2

责任者: Wang, Shih-Han;Chou, Tse-Chuan;Liu, Chung-Chiun 单位: Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan 来源出处: Sensors and Actuators, B: Chemical,2003,94(3):343-351 摘要: Sensitive porous tungsten oxide nano-crystalline based NO2 sensor was fabricated by thin film microfabrication technique. The sensitivity of this NO2 sensor was at parts per billion (ppb) level. The nano-crystalline porous tungsten oxide film was prepared from WCl6 by a sol-gel technique. The surface morphology and sensitivity to NO2 of the tungsten oxide films calcined at various temperatures were investigated. The NO2 adsorption behavior on the tungsten oxide surface was carried out by XPS measurement. Experimental results indicated that the tungsten oxide film calcined at 550°C for 1h showed the best performance as a sensing material to NO2, and the optimal operational temperature of the sensor was 300 °C. The sensor showed high sensitivity to low NO2 concentration in the range from 50 to 550 ppb with relatively fast response time ( [similar to] 3 min) and recovery time ( [similar to] 1 min), respectively. © 2003 Elsevier B.V. All rights reserved. 关键词: Chemical sensors;Nitrogen oxides;Nanostructured materials;Tungsten compounds;Sol-gels;Adsorption;Sensitivity analysis;Organic vapors