微流控技术制备ZnO纳米线阵列及其气敏特性

利用微流控技术在微通道中制备了Zn O纳米线阵列,通过X射线衍射和扫描电子显微镜分别对纳米线的物相和表面形貌进行了表征.结果发现,合成的Zn O纳米线具有良好的c轴择优取向性和结晶度.同时,对Zn O纳米线阵列在丙酮、甲醇和乙醇气体中的气敏特性进行了研究,测试结果表明:在最佳工作温度(475?C)下,纳米线阵列对200 ppm(1 ppm=10-6)丙酮气体的最大灵敏度可达8.26,响应恢复时间分别为9和5 s;通过与传统水热法制备的Zn O纳米线的气敏性能相比较发现,基于微流控技术制备的纳米线阵列具有更高的灵敏度和更快的响应恢复速度.最后,从材料表面氧气分子得失电子的角度对Zn O纳米线气敏机理进行了讨论.

Fabrication and characteristics of ZnO nanowires array gas sensor based on microfluidics

In this paper, ZnO nanowire (ZnO NW) array is prepared based on microfluidic technology. The crystalline structures and morphologies of as-synthesized ZnO NWs are characterized by X-ray diffraction and scanning electron microscopy. The results show that ZnO NW is high-quality crystalline and c-axis oriented. At the same time, the gas-sensing properties of ZnO NWs are investigated for different gases, such as acetone, methanol and ethanol. The measured results prove that ZnO NW shows a sensitivity of 8.26 at 475 ℃, and the response and recovery times can reach 9 and 5 s separately, when exposed to 200 ppm (1 ppm=10^-6) acetone. Compared with the method of conventional hydrothermal technology, the ZnO NWs based on microfluidic technology shows high sensitivity and fast recovery time. Finally, the gas sensing mechanism of ZnO NWs is also discussed from the aspect of gain and lose electron of oxygen molecules on material surface.
Keywords：zinc oxide nanowiresmicrofluidic technologyhydrothermal methodgas-sensing properties