Effects of H₂ and CO on Electrical Properties of Pure SnO₂ and Pt-Doped SnO₂ Ceramics

Abstract:

Pure SnO₂ and Pt doped SnO₂ (0≤Pt≤10wt.%) ceramics have been successfully fabricated in the form of pellet by sintering at 1000 °C for 3 h. The resistance of the samples in air and in reducing gases (200 ppm H₂ and 200 ppm CO) was determined by measuring current – voltage (I-V) characteristics via two-probe method between 150 to 450 °C. All samples show a decrease in resistance with an increase in temperature both in air and in gases. However, the values of resistance in gases are lower compared when the same samples were in air, due to gas molecules reactions with surface oxygen species which affect potential barrier to decrease and causes resistance to reduce. The resistance of the doped samples also increased by 279 - 1226% with an increase in Pt doping in SnO₂, due to Pt surface states density.

• Periodical: Materials Science Forum (Volume 846)
• Pages: 91-95
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.846.91
• Online since: March 2016
• Authors: Aiza Masyati Mas'ut*, Zaidan Abdul Wahab, Wan Mahmood Mat Yunus, Khamirul Amin Matori
• Keywords: Co, H₂, Pt, Resistance, SnO₂, Two-Probe Method

References

[1] W.J. Moon J.H. Yu, and G.M. Choi, Selective gas detection of SnO2-TiO2 gas sensors, J. Electroceram., 13 (2004) 707–713.

DOI: 10.1007/s10832-004-5180-1

[2] M.T. Wu, X. Yao, Z.H. Yuan, H.T. Sun, W.C. Wu, Q.H. Chen, and G.Y. Xu, Effect of noble metal catalyst on titania exhaust gas oxygen sensor, Sens. and Act. B. 13-14 (1993) 491.

DOI: 10.1016/0925-4005(93)85060-n

[3] K.D. Schierbaum, U.K. Kirner, J.F. Geiger and W. Gopel, Schottky barrier and conductivity gas sensors based upon Pd/SnO2 and Pt/TiO2, Sens. and Act. B 4 (1991) 87-94.

DOI: 10.1016/0925-4005(91)80181-i

[4] Z. Ibrahim, Characterisation Of Sub-Micron Platinum-Doped Stannic Oxide Ceramics For Methane Sensing In Air, PhD Thesis (2004) Universiti Teknologi Malaysia.

[5] A. Cabot, A. Dieguez, R. Romano, J.R. Morante, and N. Barsan, Influence of the catalytic introduction procedure on the nano-SnO2 gas sensor performances-where and how stay the catalytic atoms, Sens. and Act. B 79 (2001) 98-106.

DOI: 10.1016/s0925-4005(01)00854-1

[6] A. Khodadadi, S.S. Mohajerzadeh, Y. Mortazavi, and A.M. Miri, Cerium oxide/SnO2-based semiconductor gas sensors with improved sensitivity to CO, Sens. and Act. B 80 (2001) 267-271.

DOI: 10.1016/s0925-4005(01)00915-7

[7] V. Aroutiounian, Metal oxide hydrogen, oxygen, and carbon monoxide sensors for hydrogen setups and cells, Int. J. Hydrog Energy 32 (2007) 1145-1158.

DOI: 10.1016/j.ijhydene.2007.01.004

[8] A. Gurlo, N. Barsan and U. Weimar, Gas sensors based on semiconducting metal oxides, Metal Oxides, Chemistry and Applications. CRC Press, 2006, pp.683-738.

DOI: 10.1201/9781420028126.ch22

[9] N. Donato, M. Latino, andG. Neri, Book Chapter 14; Novel carbon nanotubes-based hybrid composites for sensing applications, in Bianco, S., (Eds. ) Carbon Nanotubes - From Research To Applications. InTech., 2011, pp.229-242.

DOI: 10.5772/18855