Fabrication of sandwich nanostructure graphene/polyaniline hollow spheres composite and its applications as electrode materials for supercapacitor

A novel three-dimensional (3D) reduced graphene oxide/polyaniline hollow spheres (RGO/PANI-HS) composite, in which PANI-HS were inserted between RGO layers, has been fabricated as electrode materials for supercapacitor applications. This 3D nanostructure was constructed by electrostatic interaction between SiO2@polyaniline core-shell spheres and graphene oxide, reduction of graphene oxide and removal of SiO2 in sequence. Due to its tailored nanostructure and over-all conductive network, RGO/PANI-HS electrode exhibits a high specific capacitance of 529 F g(-1) at 0.5 Ag-1 and excellent rate capability (remains 72% even at 10 A g(-1)), which is much higher than that of PANI-HS electrode (424 F g(-1) at 0.5 A g(-1), 62% retention at 10 A g(-1)) in 1 M H2SO4 aqueous solution. More importantly, RGO/PANI-HS composite can maintain 85% of its initial specific capacitance well above 51% for PANI-HS after 1000 cycles, suggesting a superior electrochemical cyclic stability. (C) 2015 Elsevier Ltd. All rights reserved.