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Hydrogen sensor based on MWNTs/WO 3

Azam, I. Z ; Sharif University of Technology

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  1. Type of Document: Article
  2. DOI: 10.1109/ICSENS.2011.6126918
  3. Abstract:
  4. In this article we report hydrogen sensing property of WO 3/MWNTs thin films that were fabricated by spin-coating on alumina substrates. The MWNTs were initially functionalized (f-MWNTs) to enhance dispersion in the sol of multiwalled carbon nanotubes (MWNTs) and tungsten trioxide (WO 3). Microstructure, morphology and chemical composition of the materials were characterized by SEM, TEM, XRD and XPS methods. Our results show WO 3 nanoparticles were nucleated on oxygenated group on surface of f-MWNTs in hybrid suspension. After annealing the films at 350 °C, electrical conductance measurements at different operating temperature were performed and the results indicates rather fast and linear sensitivity as a function of hydrogen concentrations (0.0024% to 1.14%). The gas sensitivity are suggested to arise mainly from the increase in surface area as well as development of two types of depletion layers, one at the n-WO 3/ p-MWNTs hetero junction and the other at WO 3 grain boundaries
  5. Keywords:
  6. Alumina substrates ; Chemical compositions ; Depletion layer ; Electrical conductance ; Functionalized ; Gas sensitivity ; Hybrid suspension ; Hydrogen concentration ; Hydrogen sensing properties ; Hydrogen sensor ; Linear sensitivity ; Operating temperature ; Surface area ; Tungsten trioxide ; XRD ; Alumina ; Grain boundaries ; Hydrogen ; Sols ; Tungsten ; Sensors
  7. Source: Proceedings of IEEE Sensors ; 2011 , Pages 5-7 ; 9781424492886 (ISBN)
  8. URL: http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6126918