Abstract: TeO2 nanowires were synthesized on Aucoated Si substrate by thermal evaporation using Te metal as the source material. The gas sensor was prepared by using TeO2 nanowires as the sensing material. Microstructural characterization by means of XRD， SEM and TEM showed that TeO2 nanowires were single phase of tetragonal structure. The nanowires were approximately several tens of micrometers in length and 80~600nm in diameter. No Au particles existed at the top of TeO2 nanowires， revealing that the growth of TeO2 nanowires occurred in vaporsolid mechanism. The gas sensing measurements indicated that TeO2 nanowires showed a ptype electrical conduction and reversible response to NO2 gas at room temperature. The sensitivity showed a linear increase with the increasing of NO2 gas volume fraction. The gas sensing mechanism of TeO2 nanowire sensor was investigated preliminarily.

Key words: tellurium dioxide, nanowire, nitrogen dioxide, gas sensor, gas sensing property