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Journal of Nanomaterials
Volume 2012 (2012), Article ID 612420, 9 pages
http://dx.doi.org/10.1155/2012/612420
Research Article

Gas Sensing Properties and Mechanism of Nano-SnO2-Based Sensor for Hydrogen and Carbon Monoxide

State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing University, Chongqing 400030, China

Received 17 September 2012; Revised 27 October 2012; Accepted 4 November 2012

Academic Editor: Wen Zeng

Copyright © 2012 Weigen Chen et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Nano-SnO2 powder was prepared by the hydrothermal method in this paper. X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the composition of the crystalline phase and the morphology of the prepared gas-sensitive materials, respectively. In particular, the study focused on the sensing behaviors of nano-SnO2-based sensor towards power transformer fault gases such as hydrogen and carbon monoxide. The optimum working temperature for hydrogen and carbon monoxide is about 400C and 360C, separately. Further investigations into the adsorption process of gas molecule on SnO2 (110) surface based on the first principles were conducted. The calculations indicated that 1σ orbits of H2 split into several new electronic peaks and 5σ orbits of CO almost degenerated completely in the adsorption process, which promoted charge transfer between gas molecule and SnO2 (110) surface. It provides a qualitative explanation for the prepared nano-SnO2-based sensor exhibiting different gas sensing properties towards H2 and CO.