Sensitivity properties of a novel NO2 gas sensor based on mesoporous WO3 thin film

Mesoporous WO3 thin films micro-gas sensor was fabricated and the NO, gas-sensing as well as electrical properties have been investigated. The film had nano-sized grains, porous structure with a relative surface area of 143 m(2)/g as calcined at 250 degreesC. Upon exposure to NO2, the electrical resistance of a semiconducting mesoporous WO3 thin films is found to dramatically increase. The sensitivity of mesoporous WO3 thin film sensors is substantially higher than that from other reports. In addition, the mesoporous WO3 thin film sensor calcined at 250 degreesC and operated at 35 degreesC shows an excellent sensitivity of 23, as we know it is unique NO2 gas sensor which has the sensitivity at such a low temperature. (C) 2003 Elsevier B.V. All rights reserved.