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

Abstract

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 529Fg−1 at 0.5Ag−1 and excellent rate capability (remains 72% even at 10Ag−1), which is much higher than that of PANI-HS electrode (424Fg−1 at 0.5Ag−1, 62% retention at 10Ag−1) in 1M 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.