Room Temperature Ammonia Gas Sensing Characteristics of Co3O4

Authors P.N. Shelke1,2, S.R. Jadkar2, Y.B. Khollam3, S.D. Chakane4, A.D. Adsool5, K.C. Mohite2

1 Baburaoji Gholap College, New Sangvi, Pune 411 027, India

2 School of Energy Studies, Department of Physics, University of Pune, Pune 411 007, India

3 Arts, Commerce and Science College, Pirangut, 411 042, India

4 Department of Environmental Science, University of Pune, Pune 411 007, India

5 Vidya Prithisthan of Arts, Science and Commerce College, Baramati, Pune, India

Issue Volume 3, Year 2011, Number 1, Part 5
Dates Received 04 February 2011, published online 08 December 2011
Citation P.N. Shelke, S.R. Jadkar, Y.B. Khollam, et al., J. Nano- Electron. Phys. 3 No1, 859 (2011)
PACS Number(s) 07.07.Df, 82.47.Rs, 51.70.+f
Keywords Co3O4 (2) , Ammonia sensor (2) , Sensitivity (11) , Repeatbility, Response & recovery time.
Room temperature ammonia gas-sensing characteristics of Co3O4 pellet sensor are reported in this paper. For this purpose, Co3O4 powder is prepared by a route of simple precipitation + heating at 800 °C/2 hr. The as-prepared powder is characterized by using X-ray diffraction and scanning electron microscopy. The ammonia gas-sensing properties of Co3O4 pellets made at various loads of 3, 5, 7 & 9 ton and at constant time = 4 min. are measured using home-built static gas sensing system. The characterization studies revealed that the cobalt oxide particles formed are cubic spinel Co3O4, highly pure and spherical in shape. The particle size distribution is found to be nearly uniform with average particle size ~ 1 µm. The ammonia gas sensing properties of Co3O4 pellet sensor are found to be good. The highest sensitivities – S.F. = 175 and 358 are found at ~ 25 ppm and 250 ppm concentrations of ammonia gas respectively for the Co3O4 pellet sensor made at the load = 3 ton. Further, an admirable repeatability and reversibility in the ammonia gas sensing characteristics are observed for all the Co3O4 pellet sensors. The average response time of 4.0 min. and recovery time of 3.0 min. are obtained for all the Co3O4 pellet sensors.

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