Synthesis and NO2-sensing Properties of One-dimensional Tungsten Oxide Nanowire Bundles

Nanowire bundles of tungsten oxide were synthesized by solvothermal method with tungsten hexachloride (WCl(6)) as precursor and 1-propanol as solvent. The synthesis processes were preformed at different WCI6 concentration. Long W(18)O(49) nanow ire bundles with effective surface area of 89.89 m(2)/g was synthesized at a WCl(6) concentration of 0.01M. With concentration increasing, the nanowire bundles became shorter and thicker and finally a nanoplates structure formed. The measurements for NO(2)-sensing properties indicated that the longer and thinner W(18)O(49) nanowire bundles showed the quickest response/recovery and the highest sensitivity to different concentration NO(2) gas due to their special structural feature, and the response time, recovery time and sensitivity are 19 s, 112 s and 123.6 to 5 ppm NO(2), respectively.