Fabrication Of Polyaniline/graphene/titania Nanotube Arrays Nanocomposite And Their Application In Supercapacitors

In recent years, supercapacitor has been a kind of environmentally friendly energy storage for its advantages, such as high energy density, rapidly charge-discharge ability, long-term cycle life, etc. Supercapacitor electrode materials can be basically divided into three types, carbon material, metal oxide and conductive polymer. Preparing supercapacitor electrode materials with synergistic effect is a hot spot in the present study. Polyaniline(PANI), severs as a conductive polymer with special structure, is one of the most popular materials for supercapacitor electrode, because the polymer owns controlled conductivity, reversible redox states, ease of synthesis, high storage capacity. However, during the charge/discharge process, the swelling/shrinkage of PANI causes volume changes and destroys the backbone of polymer, which seriously weaken the charge–discharge cycle life. Graphene(GE) and titanium dioxide nanotube arrays(Ti O2 NTs), because of its unique performance, have been hot topics. To combine GE, Ti O2 NTs with PANI to prepare a composite electrode material can further improve the performance of PANI base material and capacitor performance.In this paper, Ti O2 NTs were prepared firstly. And then PANI/Ti O2 NTs(PTNs)composites were prepared by solution polymerization method. The composite materials with PANI inevitable accumulation in the tube result in the poor stability. Based on this, our study introduced GE and synthetized PANI/GE/Ti O2 NTs(PGTNs)composite material. Aniline(An) concentration, HCl concentration and the amount of GE were discussed on the various properties of the composites through test and analysis of electrochemical properties. The characterization of structure and morphology of composite materials were recorded by Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray diffraction and scanning electron microscopy. The effect of GE, the specific capacitance and cycle life were investigated in 1 M HCl electrolyte. In addition, we also prepared PANI/Ti O2 nanoparticles(PT-NPs)composites and PANI/GE/Ti O2 nanoparticles(PGT-NPs)composites by using Ti O2 nanoparticles and studied the structure and properties of PGT-NPs and PT-NPs.The experiments showed that when c(An) was 0.1 mol/L, c(HCl) was 1 mol/L, and the content of GE was 8% of An, PGTNs composite material obtain the best electrochemical performance. SEM analysis showed that GE made the PANI nanowires on Ti O2 NTs more orderly, increased the effective use of PANI. Electrochemical tests showed that the specific capacitance of PGTNs composite was as high as 933 F·g-1 at a current density of 0.75 A g-1.The retention rate of specific capacitance was 91% at a current density of 10 A g-1 after constant charge–discharge 1000 cycles. Both specific capacitance and stability were higher than that of PTNs. After the characterization for PGT-NPs, PT-NPs and PANI, the capacitance were 540, 456 and 351 F·g-1 at a current density of 0.75 A g-1, respectively. The retention rate of specific capacitance were 84.6%, 79% and 56% at 10 A g-1 after 1000 cycles, respectively. It could be concluded that the electrochemical properties of nanotube array composite material was significantly better than that of granular composites.