Flowerlike Fe2O3–polyaniline nanocomposite as electrode for supercapacitor

We report the synthesis of a binary nanocomposite of Fe2O3 and polyaniline (PAni) using a facile two-step process in which Fe2O3 nanohexagons are hydrothermally produced in the first step and then these nanohexagons are embedded in PAni via in situ polymerization of aniline. Electron microscopic and X-ray diffraction analyses of the synthesized Fe2O3–PAni composite revealed a flowerlike nanoscale architecture with the flowers ranging around 400 nm in size. When tested as electrode for supercapacitor, Fe2O3–PAni nanoflower composite exhibited specific capacitance as high as 1033 F/g at a scan rate of 5 mV/s and upto 82% charge retention after 1500 charge–discharge cycles. Electrochemical impedance spectroscopy (EIS) showed a much lower charge transfer and equivalent series resistance values for the Fe2O3–PAni nanocomposite electrode compared to that of bare Fe2O3 nanohexagon-based electrode. The outstanding electrochemical performance of the composite arises from the nanoflowerlike architecture of the electrode material and good chemical bonding between Fe2O3 and PAni, resulting in high surface area and good electrical conductivity. Thus, we show that the nanoflowerlike Fe2O3–PAni composite can be a good candidate as electrode material for supercapacitor.