SYNTHESIS AND CHARACTRAZATION OF POLYANILINE/TiO2/ GRAPHITE NANOCOMPOSITE FOR SUPERCAPACITOR

Abstract

Polyaniline (PANI) and PANI/TiO2 composite was potentio dynamically deposited from solutions of 0.1M aniline /1M HCl and in the presence of 0.04 g TiO2 on bare and graphite (Gr) modified glassy carbon (GC) electrode. These materials and PANI/TiO2/Gr was also prepared chemically using in situ oxidation polymerization method to compare their electrochemical and capacitive property. The nano composite characterized using scanning electron microscope (SEM), X-ray electron diffraction (XRD), Ultra violet visible (Uv-vis) and Fourier transforms infrared (FTIR) spectroscopy. The morphology of PANI/TiO2/Gr exhibited uniform and revels good pores. The crystal size of the nano composites are estimated from XRD. Besides Uv-vis and FTIR result indicates the presences of PANI and the success full preparation of the nano composites. The electro chemical characterization of PANI, PANI/TiO2 and PANI/TiO2/Gr was carried out by employing cyclic voltametry (CV) and electrochemical impedance spectroscopy (EIS).CV analysis showed a higher specific capacitance of PANI/TiO2/Gr (4864 F/g) for 10 potential cycles) electro chemically formed on Gr/GC electrodes at scan rate of 10 mV/s than PANI (642 F/g) and PANI/TiO2 (2539 F/g).While the specific capacitance of chemically formed once was slightly lower PANI/TiO2/Gr (1944 F/g), PANI (713 F/g), PANI/TiO2 (1587 F/g). The dependence of capacitance with scan rate investigation illustrates, drops slowly from its initial value as the scan rate increases. The stability of the nano composites studied using CV at scan rate of 50 mV/s indicates the better performance of PANI/TiO2/Gr nano composites which retains 81% of its capacitance at 50th cycle. In addition to this, a large specific energy 0.0659 J and specific energy density 2259 Wh/Kg was found for PANI/TiO2/Gr. Furthermore, EIS study indicates the charge transfer resistance (Rct) and solution resistance (Rs) of the PANI/TiO2/Gr nanocomposites revels very low than PANI and PANI/TiO2. The study demonstrates the materials for electro chemical capacitors with advantages including low charge transfer resistance, high specific energy density and stability due to synergistic effects of each component on electro chemical, structure, morphology and conductivity.