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利用介电泳法在铬-银-金微电极上制备了本征多壁碳纳米管(MWNTs)气体传感器及不同基团修饰多壁碳纳米管(MWNTs-x,x:NH2,OH,COOH)气体传感器,考察了MWNTs和MWNTs-x在非均匀电场中的介电响应行为,将8 V,2 MHz的电泳参数确定为多壁碳纳米管气体传感器的制备条件;在介电泳力作用下MWNTs和MWNTs-x的颗粒均被捕获到电极尖端,发生了正介电泳(p-DEP).室温下研究了制备的气体传感器对不同浓度二氧化硫(SO2)的气敏性能,研究发现传感器对SO2的响应时间、恢复时间和灵敏度随SO2气体浓度的增加而增大,不同基团修饰MWNTs气体传感器对SO2的灵敏度较本征MWNTs传感器的灵敏度显著提高,氨基修饰MWNTs(MWNTs-NH2)气体传感器的灵敏度最高,为本征MWNTs气体传感器的17–23倍,碳管与SO2间的毛细力、表面张力、氢键、化学键等相互作用为影响传感器气敏性能的因素.
In this study, intrinsic MWNTs gas sensors and different groups of MWNTs-x, x: NH2, OH, COOH were prepared on chromium-silver-gold microelectrodes by dielectrophoresis Gas sensor was used to investigate the dielectric response of MWNTs and MWNTs-x in non-uniform electric field. The electrophoretic parameters of 8 V and 2 MHz were determined as the preparation conditions for the multi-walled carbon nanotube gas sensor. Under the action of dielectrophoretic force, MWNTs And the particles of MWNTs-x were captured at the tip of the electrode, and the positive dielectric constant (p-DEP) occurred.The gas sensing performance of the prepared gas sensors for different concentrations of sulfur dioxide (SO2) was studied at room temperature. The response time, recovery time and sensitivity increase with the increase of SO2 concentration. The sensitivities of different groups of modified MWNTs gas sensors to SO2 are significantly higher than those of intrinsic MWNTs sensors. The sensitivity of MWNTs-NH2 gas sensors The highest factor is the sensor’s gas sensitivity, which is 17-23 times of the intrinsic MWNTs gas sensor, the capillary force, surface tension, hydrogen bond and chemical bond between the carbon nanotube and SO2.