{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,13]],"date-time":"2026-04-13T23:54:58Z","timestamp":1776124498895,"version":"3.50.1"},"reference-count":25,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2013,9,17]],"date-time":"2013-09-17T00:00:00Z","timestamp":1379376000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>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\u20135 ppm in air) were investigated at 100 \u00b0C or 200 \u00b0C. 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.<\/jats:p>","DOI":"10.3390\/s130912467","type":"journal-article","created":{"date-parts":[[2013,9,17]],"date-time":"2013-09-17T12:31:17Z","timestamp":1379421077000},"page":"12467-12481","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":118,"title":["NO and NO2 Sensing Properties of WO3 and Co3O4 Based  Gas Sensors"],"prefix":"10.3390","volume":"13","author":[{"given":"Takafumi","family":"Akamatsu","sequence":"first","affiliation":[{"name":"National Institute of Advanced Industrial Science and Technology (AIST), Advanced Manufacturing Research Institute, 2266-98 Anagahora, Shimo-Shidami, Moriyama-ku, Nagoya 463-8560, Japan"}]},{"given":"Toshio","family":"Itoh","sequence":"additional","affiliation":[{"name":"National Institute of Advanced Industrial Science and Technology (AIST), Advanced Manufacturing Research Institute, 2266-98 Anagahora, Shimo-Shidami, Moriyama-ku, Nagoya 463-8560, Japan"}]},{"given":"Noriya","family":"Izu","sequence":"additional","affiliation":[{"name":"National Institute of Advanced Industrial Science and Technology (AIST), Advanced Manufacturing Research Institute, 2266-98 Anagahora, Shimo-Shidami, Moriyama-ku, Nagoya 463-8560, Japan"}]},{"given":"Woosuck","family":"Shin","sequence":"additional","affiliation":[{"name":"National Institute of Advanced Industrial Science and Technology (AIST), Advanced Manufacturing Research Institute, 2266-98 Anagahora, Shimo-Shidami, Moriyama-ku, Nagoya 463-8560, Japan"}]}],"member":"1968","published-online":{"date-parts":[[2013,9,17]]},"reference":[{"key":"ref_1","unstructured":"American Conference of Governmental Industrial Hygienists. Available online: http:\/\/www.acgih.org."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"512","DOI":"10.1016\/j.jaci.2004.05.033","article-title":"Exhaled nitric oxide as a marker of airway inflammation for an epidemiologic study in schoolchildren","volume":"114","author":"Saito","year":"2004","journal-title":"J. Allergy Clin. Immunol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"285","DOI":"10.1016\/S0021-9673(00)85025-6","article-title":"Analysis of trace pollutants in the air by means of cryogenic gas chromatography","volume":"121","author":"Giannovario","year":"1976","journal-title":"J. Chromatogr."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"580","DOI":"10.1016\/j.snb.2011.08.032","article-title":"Semiconducting metal oxides as sensors for environmentally hazardous gases","volume":"160","author":"Wetchakun","year":"2011","journal-title":"Sens. Actuator B"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"259","DOI":"10.1016\/0250-6874(89)87078-7","article-title":"The mixed oxide Al2O3-V2O5 as a semiconductor gas sensor for NO and NO2","volume":"19","author":"Ishihara","year":"1989","journal-title":"Sens. Actuator"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"388","DOI":"10.1016\/0925-4005(95)85087-2","article-title":"Metal oxide semiconductor NO2 sensor","volume":"25","author":"Inoue","year":"1995","journal-title":"Sens. Actuator B"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"28","DOI":"10.1016\/j.snb.2010.02.040","article-title":"Fabrication of NOx gas sensors using In2O3-ZnO composite films","volume":"146","author":"Lin","year":"2010","journal-title":"Sens. Actuator B"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Tierney, M.J., Kim, H.O., Madou, M., and Otagawa, T. (1993). Microelectrochemical sensor for nitrogen oxides. Sens. Actuator B, 408\u2013411.","DOI":"10.1016\/0925-4005(93)85413-5"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"387","DOI":"10.1016\/0925-4005(93)85408-3","article-title":"Development of high-performance solid-electrolyte sensors for NO and NO2","volume":"13\u201314","author":"Miura","year":"1993","journal-title":"Sens. Actuator B"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1611","DOI":"10.1246\/cl.1991.1611","article-title":"Tungsten oxide-based semiconductor sensor highly sensitive to NO and NO2","volume":"20","author":"Akiyama","year":"1991","journal-title":"Chem. Lett."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"234","DOI":"10.1016\/j.snb.2008.01.027","article-title":"Ultrahigh-sensitive WO3 nanosensor with interdigitated Au nano-electrode for NO2 detection","volume":"132","author":"Tamaki","year":"2008","journal-title":"Sens. Actuator B"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"280","DOI":"10.1016\/j.snb.2009.11.006","article-title":"Sensing properties of atmospheric plasma-sprayed WO3 coating for sub-ppm NO2 detection","volume":"144","author":"Zhang","year":"2010","journal-title":"Sens. Actuator B"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"226","DOI":"10.1016\/S0925-4005(01)00572-X","article-title":"Detection and quantification of nitric oxide in human breath using a semiconducting oxide based chemiresistive microsensor","volume":"76","author":"Fruhberger","year":"2001","journal-title":"Sens. Actuator B"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"52","DOI":"10.1016\/S0925-4005(98)00156-7","article-title":"NOx gas sensing characteristics of WO3 thin films activated by noble metals (Pd, Pt, Au) layers","volume":"50","author":"Penza","year":"1998","journal-title":"Sens. Actuator B"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"76","DOI":"10.1016\/S0040-6090(03)00512-1","article-title":"DRIFT studies of thick film un-doped and Pd-doped SnO2 sensors: Temperature changes effect and CO detection mechanism in the presence of water vapour","volume":"436","author":"Harbeck","year":"2003","journal-title":"Thin Solid Films"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"103","DOI":"10.1016\/j.snb.2010.09.040","article-title":"CO sensing mechanism with WO3 based gas sensors","volume":"151","author":"Simion","year":"2010","journal-title":"Sens. Actuator B"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"295","DOI":"10.1380\/jsssj.14.295","article-title":"Promotion of NO sensitivity of WO3 element with the addition of noble metals","volume":"14","author":"Akiyama","year":"1993","journal-title":"J. Surf. Sci. Jpn."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"135","DOI":"10.1016\/j.snb.2012.09.097","article-title":"Nonanal gas sensing properties of platinum, palladium, and gold-loaded tin oxide VOCs sensors","volume":"187","author":"Itoh","year":"2013","journal-title":"Sens. Actuator B Chem."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1707","DOI":"10.1021\/la011428u","article-title":"Identification of surface sites on monoclinic WO3 powders by infrared spectroscopy","volume":"18","author":"Kanan","year":"2002","journal-title":"Langmuir"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"4673","DOI":"10.1021\/jp993894m","article-title":"Infrared and TPD studies of nitrates adsorbed on Tb4O7, La2O3, BaO, and MgO\/\u03b3-Al2O3","volume":"104","author":"Chi","year":"2000","journal-title":"J. Phys. Chem. B"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"442","DOI":"10.1016\/S0021-9517(03)00084-8","article-title":"Adsorption of NO on promoted Ag\/\u03b1-Al2O3 catalysts","volume":"217","author":"Vannice","year":"2003","journal-title":"J. Catal."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"176","DOI":"10.1016\/S0040-6090(01)00979-8","article-title":"In situ diffuse reflectance infrared spectroscopy study of CO adsorption on SnO2","volume":"391","author":"Emiroglu","year":"2001","journal-title":"Thin Solid Films"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"85","DOI":"10.1016\/S0925-4005(98)00160-9","article-title":"Gas-kinetic interactions of nitrous oxides with SnO2 surface","volume":"50","author":"Ruhland","year":"1998","journal-title":"Sens. Actuator B"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"291","DOI":"10.1016\/j.snb.2004.04.075","article-title":"A p- to n-transition on \u03b1-Fe2O3-based thick film sensors studied by conductance and work function change measurements","volume":"102","author":"Gurlo","year":"2004","journal-title":"Sens. Actuator B"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"298","DOI":"10.1016\/j.snb.2008.08.026","article-title":"CuO nanowire gas sensors for air quality control in automotive cabin","volume":"135","author":"Kim","year":"2008","journal-title":"Sens. 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