Abstract: W-doped ZnO nanowires were synthesized by a hydrothermal method using zinc dichloride (ZnCl2·2H2O) and sodium carbonate (Na2CO3) as the precursor， as well as sodium tungstate (Na2WO4·2H2O) as the tungsten source. The microstructural characterization by means of X-ray diffraction microscopy (XRD) and scanning electron microscopy (SEM) showed that the structure and morphology of ZnO nanowires were not affected by W doping. The obtained products with diameter of 50~80 nm and length of 2.0~5.2 μm were ZnO nanowires with hexagonal wurtzite structure ， which possessed smooth surface， high crystallinity， and good dispersion. NO2 sensing measurements indicated that 1% W-doped ZnO nanowires achieved the highest sensor response at an operating temperature of 200 ℃ and good selectivity， reversibility and reproducibility. The gas sensing mechanism was discussed in accordance with the electron depletion layer theory and reactive site.

Key words: ZnO nanowires, W doping NO2, Gas sensing property, Mining safety