Journal of Sol-Gel Science and Technology

, Volume 22, Issue 1–2, pp 167–179 | Cite as

Sol-Gel Processed TiO2-Based Nano-Sized Powders for Use in Thick-Film Gas Sensors for Atmospheric Pollutant Monitoring

  • Enrico Traversa
  • Maria Luisa Di Vona
  • Silvia Licoccia
  • Michele Sacerdoti
  • Maria Cristina Carotta
  • Luigi Crema
  • Giuliano Martinelli


Sol-gel routes were used to prepare pure and 5 at% and 10 at% Ta- or Nb-dope TiO2 nano-sized powders. The thermal decomposition behaviour of the precursors was studied using simultaneous thermogravimetric and differential thermal analysis (TG/DTA). X-ray diffraction (XRD) analysis showed that the powders heated to 400°C were crystalline in the anatase TiO2 structure. The pure TiO2 powder heated to 850°C showed the rutile structure. The addition of Ta and Nb inhibited the anatase-to-rutile phase transformation up to 950–1050°C. Ta was soluble in the titania lattice up to the concentration of 10 at%, while the solubility of Nb was 5 at%. Thick films were fabricated with these powders by screen printing technology and then fired for 1 h at different temperatures in the 650–1050°C range. Scanning electron microscopy (SEM) observations showed that the anatase-to-rutile phase transformation induces a grain growth of about one order of magnitude for pure TiO2. The addition of Ta and Nb is effective to keep the TiO2 grain size at a nanometric level even at 950°C, though grain growth was observed with increasing temperature. The gas-sensitive electrical response of the thick films were tested in laboratory, in environments with CO in dry and wet air. Conductance measurements showed a good gas response only for the nanostructured titania-based films. For field tests, the prototype sensors were placed beside a conventional station for atmospheric pollutant monitoring. The electrical response of the thick films was compared with the results of the analytical instruments. The same trend was observed for both systems, demonstrating the use of gas sensors for this aim.

gas sensors titania nano-sized powders thick films atmospheric pollutant monitoring 


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  1. 1.
    E. Traversa, J. Am. Ceram. Soc. 78, 2625 (1995).Google Scholar
  2. 2.
    N. Yamazoe and N. Miura, IEEE Trans. Compon., Packag., Manuf. Technol. A 18, 252 (1995).Google Scholar
  3. 3.
    E. Traversa, in Progress in Ceramic Basic Science: Challenge Toward the 21st Century, edited by T. Hirai, S.I. Hirano, and Y. Takeda (The Basic Science Division, The Ceramic Society of Japan, Tokyo, Japan, 1996), p. 145.Google Scholar
  4. 4.
    T. Seiyama, A. Kato, K. Fujiishi, and N. Nagatani, Anal. Chem. 34, 1502 (1962).Google Scholar
  5. 5.
    N. Taguchi, Japanese Patent Application No. 45-38200 (1962).Google Scholar
  6. 6.
    Y. Shimizu and M. Egashira, MRS Bull. 24(6), 18 (1999).Google Scholar
  7. 7.
    C. Xu, J. Tamaki, N. Miura, and N. Yamazoe, Sensors and Actuators B 3, 147 (1991).Google Scholar
  8. 8.
    G. Williams and G.S.V. Coles, MRS Bull. 24(6), 25 (1999).Google Scholar
  9. 9.
    E. Traversa, J. Intelligent Mater. Systems and Structures 6, 860 (1995).Google Scholar
  10. 10.
    C.N.R. Rao, J. Mater. Chem. 9, 1 (1999).Google Scholar
  11. 11.
    H. Hahn, Nanostruct. Mater. 2, 251 (1993).Google Scholar
  12. 12.
    J.Y. Ying and T. Sun, J. Electroceram. 1, 219 (1997).Google Scholar
  13. 13.
    J.Y. Ying, Sol-Gel Derived Materials, Chem. Mater. special issue 9, 2247 (1997).Google Scholar
  14. 14.
    I. Chen, L. Gao, J. Huang, and D. Yan, J. Mater. Sci. 31, 3497 (1996).Google Scholar
  15. 15.
    Y. Xu, K. Yao, X. Zhou, and Q. Cao, Sensors and Actuators B 14, 492 (1993).Google Scholar
  16. 16.
    R.K. Sharma, M.C. Bhatnagar, and G.L. Sharma, Appl. Surf. Sci. 92, 647 (1996).Google Scholar
  17. 17.
    H. Tang, K. Prasad, R. Sanjinées, and F. Lévy, Sensors and Actuators B 26/27, 71 (1995).Google Scholar
  18. 18.
    M.C. Carotta, M.A. Butturi, G. Martinelli, M.L. Di Vona, S. Licoccia, and E. Traversa, Electron Technol. 33, 113 (2000).Google Scholar
  19. 19.
    E. Traversa, M.L. Di Vona, S. Licoccia, M. Sacerdoti, M.C. Carotta, M. Gallana, and G. Martinelli, J. Sol-Gel Sci. Technol. 19, 193 (2000).Google Scholar
  20. 20.
    D.C. Hague and M.J. Mayo, J. Am. Ceram. Soc. 77, 1957 (1994).Google Scholar
  21. 21.
    G. Martinelli, M.C. Carotta, M. Ferroni, Y. Sadaoka, and E. Traversa, Sensors and Actuators B 55, 99 (1999).Google Scholar
  22. 22.
    G. Martinelli, M.C. Carotta, E. Traversa, and G. Ghiotti, MRS Bull. 24(6), 30 (1999).Google Scholar
  23. 23.
    E. Traversa, Y. Sadaoka, M.C. Carotta, and G. Martinelli, Sensors and Actuators B 65, 181 (2000).Google Scholar
  24. 24.
    M.C. Carotta, G. Martinelli, L. Crema, M. Gallana, M. Merli, G. Ghiotti, and E. Traversa, Sensors and Actuators B 68, 1 (2000).Google Scholar
  25. 25.
    G. Martinelli and M.C. Carotta, Sensors and Actuators B 23, 157 (1995).Google Scholar
  26. 26.
    N.M. White and J.D. Turner, Meas. Sci. Technol. 8, 1 (1997).Google Scholar
  27. 27.
    R.A. Young, A. Sakthivel, T.S. Moss, and C.O. Paiva-Santos, J. Appl. Cryst. 28, 366 (1995).Google Scholar
  28. 28.
    M.C. Carotta, C. Dallara, G. Martinelli, L. Passari, and A. Camanzi, Sensors and Actuators B 3, 191 (1991).Google Scholar
  29. 29.
    M.K. Akhtar, S.E. Pratsinis, and S.V.R. Mastrangelo, J. Am. Ceram. Soc. 75, 3408 (1992).Google Scholar
  30. 30.
    S.R. Morrison, Sensors and Actuators 2, 329 (1982).Google Scholar
  31. 31.
    V. Lantto, P. Romppainen and S. Leppävuori, Sensors and Actuators 14, 149 (1988).Google Scholar
  32. 32.
    P.K. Clifford and D.T. Tuma, Sensors and Actuators 3, 255 (1982/83).Google Scholar
  33. 33.
    E. Traversa, Sensors and Actuators B 23, 135 (1995).Google Scholar
  34. 34.
    E. Traversa, S. Villanti, G. Gusmano, H. Aono, and Y. Sadaoka, J. Am. Ceram. Soc. 82, 2442 (1999).Google Scholar

Copyright information

© Kluwer Academic Publishers 2001

Authors and Affiliations

  • Enrico Traversa
    • 1
  • Maria Luisa Di Vona
    • 1
  • Silvia Licoccia
    • 1
  • Michele Sacerdoti
    • 2
  • Maria Cristina Carotta
    • 3
  • Luigi Crema
    • 3
  • Giuliano Martinelli
    • 3
  1. 1.Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali (INSTM) & Dipartimento di Scienze e Tecnologie Chimiche, Università di Roma “Tor Vergata”RomaItaly
  2. 2.Istituto di MineralogiaUniversità di FerraraFerraraItaly
  3. 3.INFM—Dipartimento di FisicaUniversità di FerraraFerraraItaly

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