Preparation of cotton-shaped CNT/PANI composite and its electrochemical performances

Carbon nanotube (CNT) has been received much interest due to its unique structure, mechanical and electronic properties. Although activated CNT can enhance the specific capacitance, the effect is limited. Polyaniline (PANI) has good mechanical performance, environmental stability and reversible control of conductivity both by charge-transfer doping and protonation. So the CNT/PANI composite is an effective method to improve the performance of sample. It is well know that the composite morphology is closely with its electrochemical properties. The fibrous composite materials with the large surface area have been received much interest for their potential electrochemical performance. In this paper, the CNT/PANI composite was prepared by the Fe3O4 as template. Firstly, the acyl chloride was grafted on the surface of the CNT by series of organic chemistry reactions and the CNT-COCl was got. Then, the CNT-COCl absorbed on the surface of the Fe3O4. After that, the CNT-COCl was reaction with aniline and got the CNT amide. Then, the aniline grafted on the CNT was polymerized to PANI by in-situ chemical polymerization. Finally, the cotton-shaped CNT/PANI composite was obtained. The obtained material was characterized by the Fourier transform infrared spectroscopy, scanning electron microscope and transmission electron microscope. And the cyclic voltammograms, galvanostatic charging/discharging and cycle life testing were used to tested electrochemical performances of the obtained composite. The results show that the obtained CNT/PANI composite had high specific capacitance of 144 F/g (in organic electrolyte), which is much more than those of the pure PANI (about 71 F/g). So it may be found that the composite material has good application prospects in super capacitor field.