1. Hydrogen sensor based on MWNTs/WO3
- Author
-
Ghasempour Roghayeh and Iraji Zad Azam
- Subjects
Spin coating ,Materials science ,Hydrogen ,Annealing (metallurgy) ,chemistry.chemical_element ,Nanoparticle ,Nanotechnology ,Carbon nanotube ,Hydrogen sensor ,Tungsten trioxide ,law.invention ,chemistry.chemical_compound ,chemistry ,X-ray photoelectron spectroscopy ,Chemical engineering ,law - Abstract
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.
- Published
- 2011