3D reduced graphene oxide/MnO₂/polyaniline composite for high-performance supercapacitor

A facile approach has been developed to fabricate 3D polystyrene microsphere-reduced graphene Oxide–MnO₂–polyaniline (3DrGN–MnO₂–PANI) coaxial arrays composite by using an electro-polymerization process. In this study, PS is used as a template to form a 3D braced structure with MnO₂ nanosheets as scaffolds to assist in the formation of PANI coaxial nanoarrays. The PANI nanorods, which are composed of coaxial arrays deposited on the interlaced MnO₂ nanosheet, have a diameter of 25–30 nm, creating a number of open porous structures which are beneficial for ion transport into the electrode. Furthermore, the structure and property of the as-prepared products have been characterized by Scanning electron microscopy, Fourier transform infrared spectroscopy, Raman spectra, X-ray diffraction, X-ray photoelectron spectroscopy, Cyclic voltammetry and Galvanostatic charge–discharge tests. When the 3DrGN–MnO₂–PANI composite was tested as an electrode of the supercapacitor in a three-electrode measurement, it exhibited a high specific capacitance of 1181 F g⁻¹ at a current density of 1 A g⁻¹ with retaining 89.1% of the initial specific capacitance retained after 1000 cycles of constant charge–discharge test at a current density of 20 A g⁻¹. It is believed that the 3DrGN–MnO₂–PANI composite will have great potential for application in supercapacitors.