A SnO2 nanowires (NWs) sensor was coated with a functional La2O3 layer by solution deposition and its gas sensing characteristics were compared with those of an uncoated SnO2 NWs sensor. The responses (Ra/Rg, Ra: resistance in air, Rg: resistance in gas) of an undoped SnO2 NWs sensor to 100 ppm C2H5OH and CH3COCH3 were 10.5 and 9.6, respectively, while those to 100 ppm C3H8, CO, and H2 ranged from 3.1 to 3.3. The Ra/Rg values of the La2O3-coated SnO2 NWs to 100 ppm C2H5OH and CH3COCH3 increased to 57.3 and 34.9, respectively, but there was no significant change in the responses to C3H8, CO, and H2. The ∼5.5-fold enhancement in Ra/Rg to C2H5OH as well as the selective detection of C2H5OH in the interference gases such as C3H8, CO, and H2 was accomplished simultaneously by coating with La2O3. In particular, the selective discrimination of C2H5OH over CH3COCH3, which is a difficult issue on account their similar chemical nature, was possible.
Bibliographical noteFunding Information:
This work was supported in part by the Korea Science and Engineering Foundation (KOSEF) grant funded by the Korea government (MOST) (No. R01-2005-000-10648-0(2005)) and by the IT R&D program of MIC/IITA [2006-S-078-02, Environmental Sensing and Alerting System with Nano-wire and Nano-tube]. We thank for government for financial supports.
- Ethanol sensor
- Selective detection
- SnO nanowires
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Surfaces, Coatings and Films
- Metals and Alloys
- Electrical and Electronic Engineering
- Materials Chemistry