title: NO and NO2 sensing properties of WO3 and Co3O4 based gas sensors.
abstract: Semiconductor-based gas sensors that use n-type WO3 or p-type Co3O4 powder were fabricated and their gas sensing properties toward NO2 or NO (0.5-5 ppm in air) were investigated at 100 °C or 200 °C. The resistance of the WO3-based sensor increased on exposure to NO2 and NO. On the other hand, the resistance of the Co3O4-based sensor varied depending on the operating temperature and the gas species. The chemical states of the surface of WO3 or those of the Co3O4 powder on exposure to 1 ppm NO2 and NO were investigated by diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy. No clear differences between the chemical states of the metal oxide surface exposed to NO2 or NO could be detected from the DRIFT spectra.
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST), Advanced Manufacturing Research Institute, 2266-98 Anagahora, Shimo-Shidami, Moriyama-ku, Nagoya 463-8560, Japan. t-akamatsu@aist.go.jp.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Akamatsu
authors.forename: Toshio
authors.initials: T
authors.lastname: Itoh
authors.forename: Noriya
authors.initials: N
authors.lastname: Izu
authors.forename: Woosuck
authors.initials: W
authors.lastname: Shin
mesh_terms: D003035:Cobalt / Q000737:chemistry*; D003217:Conductometry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005740:Gases / Q000032:analysis*; D009589:Nitrogen Oxides / Q000032:analysis* / Q000737:chemistry; D010087:Oxides / Q000737:chemistry*; D012666:Semiconductors; D014159:Transducers; D014414:Tungsten / Q000737:chemistry*
chemical_list: D005740:Gases; D009589:Nitrogen Oxides; D010087:Oxides; D003035:Cobalt; C511604:tungsten oxide; C060728:cobalt oxide; D014414:Tungsten
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