Title: No_x sensing characteristics of single wall carbon nanotube gas sensor prepared by pulsed laser ablation

Authors: M.M.H. Bhuiyan, F. Mitsugi, T. Ueda, T. Ikegami

Addresses: Graduate School of Science and Technology, Department of Frontier Technology for Energy and Devices, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555, Japan. ' Graduate School of Science and Technology, Department of Frontier Technology for Energy and Devices, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555, Japan. ' Graduate School of Science and Technology, Department of Frontier Technology for Energy and Devices, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555, Japan. ' Graduate School of Science and Technology, Department of Frontier Technology for Energy and Devices, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555, Japan

Abstract: A single-walled carbon nanotube (SWCNT) gas sensor was prepared by pulsed laser ablation. A graphite composite target rod containing nickel (Ni) and cobalt (Co) was used. The repetition rate and wavelength of the laser were 10 Hz and 532 nm, respectively. Laser fluence at the target surface was approximately 2.3 J/cm². The quartz tube was heated to 1273K by an electric furnace and filled with pure argon or nitrogen gas. The pressure and gas flow rate inside the quartz furnace were 500 Torr to 760 Torr and 100 sccm, respectively. The prepared CNTs were collected as bundled SWCNTs and were dispersed in the dimethylformamide solution. The prepared CNTs were characterised by scanning and transmission electron microscope and Raman spectroscopy. The CNTs were dispersed on an Al₂O₃ substrate to prepare the sensor. The prepared SWCNT sensors were used to detect NO and NO₂ gases using two terminal resistance methods based on the change in electrical resistance due to exposure to these gases. The sensor responded to a minimum concentration of 100 ppb NO₂ gas. The resistance gradient was calculated by the polynomial curve fitting of raw data and a relationship was found between resistance gradient and gas concentration.

Keywords: pulsed laser ablation; carbon nanotubes; CNT; gas sensors; adsorption; desorption; resistance gradient; nitrogen oxides; graphite; nickel; cobalt.

DOI: 10.1504/IJNM.2009.028125

International Journal of Nanomanufacturing, 2009 Vol.4 No.1/2/3/4, pp.186 - 196

Published online: 07 Sep 2009 *

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