Functionalized single wall carbon nanotubes based gas sensor
Authors: Atashbar M.Z., Baratto C., Faglia G., Sberveglieri G.
Autors Affiliation: Department of Electrical and Computer Engineering, Western Michigan University, Kalamazoo, MI 49004, United States; C.N.R. – INFM, Department of Chemistry and Physics, University of Brescia, 25133 Brescia, Italy
Abstract: In this paper we report on functionalized single wall carbon nanotube (SWNT) based gas sensor. SWNT were functionalized with Sodium Dodecyl Sulfate (SDS) which improved solubility of SWNT in the DI water significantly. Solutions of SWNTs were deposited on the alumina substrate prepatterned with Pt contacts and heater to form sensor. The morphology of the SWNT films were characterized by Atomic Force Microscope (AFM) and transmission electron microscope (TEM) imaging and their gas sensing properties were studied using voltamperometric technique. Sensors sensitivity were tested in presence of O3 (70-350 ppb), NO2 (0.1-5 ppm), CO (500 ppm) ethanol (500ppm), and NH 3 (5ppm) diluted in humid air (50% RH). The working temperature was varied in the range 20°C-70°C. The sensors demonstrated response to ethanol gas with long response and recovery times more than one hour. Sensors showed an appreciable response to low concentrations of 70 ppb of ozone and 100 ppb of NO2 while showing virtually no response to CO and NH 3.
KeyWords: Carbon nanotubes; Chemical sensors; Diffusers (optical); Extreme ultraviolet lithography; Gas detectors; Intelligent materials; Microscopes; Nanocomposites; Nanopores; Nanostructured materials; Nanostructures; Nanotechnology; Nanotubes; Platinum; Sensors; Sodium; Sodium sulfate; Sulfate minerals; Transmission electron microscopy; Walls (structural partitions), Alumina substrates; Atomic Force Microscope; DI water; Functionalized; Gas sensors; Gas-sensing properties; Improved solubility; Single wall carbon nanotubes; Single-wall carbon nanotube; Sodium dodecyl sulfate; Transmission electron microscope, Single-walled carbon nanotubes (SWCN)DOI: 10.1109/ICSENS.2007.355758