Adsorption-template preparation of polyanilines with different morphologies and their capacitance

Four nanostructured polyanilines (PANIs) with different morphologies, including nanofibers, nanoflowers, nanorods, and nanotubes are prepared by an adsorption-template technique in acidic condition. Manganese dioxides (alpha-MnO2) with different morphologies are used as reactive templates as well as oxidants. The aniline monomers are adsorbed on the surface of alpha-MnO2 templates and then they are turn into PANIs with novel morphologies. The preparation process of the PANIs with different morphologies is topochemical reaction, and the obtained PANIs with different morphologies show not only better dispersity, but also better uniformity in size. The electrochemical measurements show that their performance is highly dependent on the morphology of PANI electrodes. The specific capacitances of PANI electrodes are 521, 543, 638, and 661 F g(-1) at a current density of 1 A g(-1) for nanofibers, nanoflowers, nanorods, and nanotubes, respectively, and their capacitive retentions are about 50, 75, 70, and 88% as the current density increases from 1 to 10 A g(-1). The PANI nanotube electrode shows the highest specific capacitance and best rate performance due to its high conductivity and good ion transportation. This method may be readily extended to the preparation of other conducting polymers with good capacitive performance. (C) 2014 Elsevier Ltd. All rights reserved.