ZnO纳米线的制备及其气敏特性

Fabrication and Gas Sensing Properties of ZnO Nanowires

采用水热法制备了ZnO纳米线,利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)对其物相及微观形貌进行了表征和分析。测试结果表明,ZnO纳米线的平均直径和长度分别约为250 nm和10μm。同时,研究了ZnO纳米线气体传感器对挥发性有机化合物(VOC)的气敏特性。实验结果表明,ZnO纳米线的气体传感器在最佳工作温度200℃下,对浓度5×10-7乙醇和丙酮气体的灵敏度分别可达4.58和2.63,相应的响应时间分别为9和6 s,恢复时间均为3 s。其最低检测极限为5×10-8,表明该传感器对不同环境中乙醇和丙酮气体的检测具有潜在应用前景。最后,对ZnO纳米线气体传感器的气敏机理进行了讨论。

ZnO nanowires were fabricated by the hydrothermal method.The phase and micro morphology of the prepared ZnO nanowires were characterized by the X-ray diffraction（XRD）,scanning electron microscopy（SEM）and transmission electron microscopy（TEM）.The measured results show that the average diameter and length of the ZnO nanowires are about 250 nm and 10μm,respectively.Meanwhile,the gas sensing properties of the ZnO nanowire gas sensor for volatile organic compounds（VOCs）were investigated.The experimental results show that the gas sensing sensitivities of the ethanol and acetone can reach to 4.58 and 2.63 under the concentration of 5×10-7 at optimal working temperature（200℃）,and the corresponding response time is 9 and 6 s respectively,and the recovery time both is3 s.Moreover,the minimum detection limit can be as low as 5×10-8,demonstrating that such ZnO nanowire gas sensor has potential gas sensing application for detecting the ethanol or acetone in different environments.Finally,the gas sensing mechanism of the ZnO nanowire gas sensor was discussed.