A three-dimensional nanostructured PANI/MnO (x) porous microsphere and its capacitive performance

作者:Huo Yuqiu*; Zhang Haiying; Jiang Jianyan; Yang Yang
来源:Journal of Materials Science, 2012, 47(19): 7026-7034.
DOI:10.1007/s10853-012-6654-1

摘要

Three-dimensional nanostructured polyaniline (PANI) and manganese oxide (MnO (x) ) composite porous microspheres were prepared by oxidizing aniline with KMnO4 under interfacial chemical synthesis with 4-amino-thiophenol (4-ATP) as the structure-directing agent on the Au substrate. Surface morphology and chemical composition of PANI/MnO (x) microsphere were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, thermo gravimetric-differential thermal analysis, and Fourier transform infrared spectrum. The result displayed that concentration of KMnO4 played a key role in forming the 3D nanostructured porous microspheres. To obtain the regular shapes and uniform sizes of the porous microspheres, the optimal concentration of oxidant was 0.15 mol L-1. The electrochemistry performances of PANI/MnO (x) microsphere were determined by cyclic voltammograms, electrochemical impedance spectroscopy, and galvanostatic charge-discharge. The specific capacitance of the 3D nanostructured PANI-MnO (x) porous microspheres exhibited a maximum value of 828 F g(-1) at current density of 2 mA cm(-2) over a potential range of 0.0-0.9 V versus SCE. It has improved 365 and 88 % comparing with that of PANI (178 F g(-1)) and MnO (x) (440 F g(-1)) obtained at the similar condition. The charge-discharge tests showed the PANI/MnO (x) microsphere possessed a good cycling stability. It maintained about 84.2 % of the initial capacitance after 1000 cycles at a current density of 2.0 mA cm(-2).