聚吡咯/碳纳米管复合纳米材料的制备、表征及其气敏性能

Polypyrrole Coated Carbon Nanotubes:Preparation,Characterization,and Gas-sensing Properties

通过原位化学氧化聚合法成功制备了聚吡咯(PPy)包裹酸处理多壁碳纳米管(F-MWCNTs)的复合材料(PPy/F-MWCNTs).对所制备的PPy/F-MWCNTs纳米复合材料,分别采用傅里叶变换红外光谱分析(FT-IR)、紫外-可见漫反射(UV-Vis DRS)、热重分析(TGA)、X射线衍射(XRD)、比表面分析(BET)、场发射扫描电镜(FE-SEM)和透射电镜(TEM)进行表征.实验结果表明:在F-MWCNTs表面均匀包覆了一层约25～40nm厚的PPy,PPy/F-MWCNTs的比表面积较单一的聚吡咯提高了近3倍.基于PPy/F-MWCNTs的气敏元件在室温下对NH3的气敏性能较单一聚吡咯和碳纳米管具有更高的灵敏度,更短的响应时间以及更好的稳定性,其中对体积浓度为200×10-6的NH3的灵敏度能达到1.9,响应时间为135s.另外与PPy包覆未经酸处理的MWCNTs相比,PPy/F-MWCNTs的灵敏度更高.

A nanocomposite（PPy/F-MWCNTs） were successfully synthesized by the in-situ chemical oxidation polymerization with acid-treated multi-walled carbon nanotubes（F-MWCNTs） and polypyrroles（PPy）.The as-prepared composite was characterized by Fourier transformed infrared spectra（FT-IR）,UV-Vis diffuse refflec-tion spectroscope（UV-Vis DRS）,thermal gravimetric analysis（TGA）,X-ray diffraction（XRD）,Branauer-Emmett-Teller analysis（BET）,field-emission scanning electron microscope（FE-SEM） and transmission electron microscope（TEM）.The results reveal that the F-MWCNTs is well coated with about 25-40nm thick polypyrrole,and the surface specific areas of PPy/F-MWCNTs is about three times than that of pure PPy.The sensors fabricated by PPy/F-MWCNTs exhibit higher sensitivity,better response/reproducibility towards NH3 vapor at room tempera-ture than that fabricated by pure PPy or F-MWCNTs.The sensitivity is 1.9 even to 200×10-6 of NH3 and the re-sponse time is 135s.In addition,compared with MWCNTs untreated with acid,the as-prepared PPy/F-MWCNTs also exhibits higher sensitivity than that prepared without acid-treated MWCNTs.