4. Thermally Stable Mesoporous SnO2 and TiO2 Powders for Semi-Conductor Gas Sensor Application

  1. Sheng Yao,
  2. Bruce Tuttle,
  3. Clive Randall and
  4. Dwight Viehland
  1. Yasuhiro Shimizu1 and
  2. Makoto Egashira2

Published Online: 26 MAR 2008

DOI: 10.1002/9780470291252.ch4

Advances in Electronic Ceramic Materials: Ceramic Engineering and Science Proceedings, Volume 26, Number 5

Advances in Electronic Ceramic Materials: Ceramic Engineering and Science Proceedings, Volume 26, Number 5

How to Cite

Shimizu, Y. and Egashira, M. (2008) Thermally Stable Mesoporous SnO2 and TiO2 Powders for Semi-Conductor Gas Sensor Application, in Advances in Electronic Ceramic Materials: Ceramic Engineering and Science Proceedings, Volume 26, Number 5 (eds S. Yao, B. Tuttle, C. Randall and D. Viehland), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470291252.ch4

Author Information

  1. 1

    Graduate School of Science Technology, 1-14 Bunkyo-machi, Nagasaki 852-8521, JAPAN

  2. 2

    Faculty of Engineering Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, JAPAN

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 2005

ISBN Information

Print ISBN: 9781574982350

Online ISBN: 9780470291252

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Keywords:

  • synthesized;
  • modification;
  • sensitization;
  • characterized;
  • semiconductor

Summary

Mesoporous and large mesoporous SnO2 and mesoprous TiO2 powders were prepared and then their potentials as semiconductor gas sensor materials have been examined. Phosphoric acid treatment of as-prepared powders was found to be effective for suppressing the crystallite growth and then maintaining their ordered mesoporous and large mesoporous structure as well as large specific surface area up to elevated temperatures. Owing to their thermally stable ordered porous structure, mesoporous and large mesoporous sensors showed larger gas response than the sensors fabricated with conventionally prepared and commercially available powders. However, the improvement in response was relatively smaller than expected from the enlargement in specific surface area. Formation of large secondary particles during the aging of the synthesized products and poisoning of active sites for gas detection, especially for mesoprous TiO2, are considered to be possible reasons for the unexpectedly small response enhancement. Simultaneous surface modification of conventional SnO2 powder, i. e. loading of Ru and subsequent coating with a mesoporous SnO2, was proved to be an effective approach in improving gas sensing properties. The improved response was considered to arise from a synergistic effect of the diffusion control by the mesoporous layer and the chemical sensitization by the Ru loaded.