Variable-temperature Raman spectroscopic study of the hydrogen sensing mechanism in Pt-WO3 nanowire film

Two special properties of Pt coated WO3 (Pt-WO3) nanowire film for sensing hydrogen gas flow in air are reported in this paper, including the large relative resistance change (close to 100%) and the dependence of the millisecond-scale response time on operating temperature. A variable-temperature Raman spectroscopic system is applied to record the structural changes of WO3 nanowires in situ during the input of H-2 gas at different operating temperatures. Furthermore, based on the experimental results, two combined models are proposed to be responsible for the hydrogen sensing mechanism in Pt-WO3 nanowire film. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4798280]