Ultrasensitive gas sensor using Co3O4-modified SnO2

U. Sung Choi, Go Sakai, Kengo Shimanoe, Noboru Yamazoe

Research output: Contribution to journalConference articlepeer-review

6 Citations (Scopus)


SnO2 powder was loaded with 0-5 % Co3O4 by mass by a ball milling method. The resulting composites were screen printed onto a substrate to test the sensing properties to CO and H2. It was found that the sensor response, defined as the ratio of electrical resistance in air to that in gas, was greatly promoted with 0.5 or 1.0 % Co 3O4 loading, while further loadings (3 or 5 %) gave an adverse effect. For the 1 % Co3O4-loaded device, for example, the responses to 100, 50 and 10 ppm CO in air were as large as 375, 181 and 23 at 250 °C, respectively, and those to 50, 10 and 1 ppm H 2 in air were 568, 181 and 53 at 300 °C, respectively. The electrical resistance in air increased significantly with increasing Co 3O4 loading, indicating an electronic interaction between Co3O4 and SnO2. The change of the electronic interaction with a change in the redox state of Co3O4 appears to be an origin of the ultra high sensitivity to CO and H2.

Original languageEnglish
Pages (from-to)101-106
Number of pages6
JournalCeramic Engineering and Science Proceedings
Issue number4
Publication statusPublished - 2003
Event27th International Cocoa Beach Conference on Advanced Ceramics and Composites: B - Cocoa Beach, FL, United States
Duration: Jan 26 2003Jan 31 2003

All Science Journal Classification (ASJC) codes

  • Ceramics and Composites
  • Materials Chemistry


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