Synthesis and capacitance performance of MnO2/RGO double-shelled hollow microsphere

The Manganese dioxide/reduced graphene oxide (MnO2/RGO) double-shelled hollow microsphere with an improved electrical conductivity and accessible surface area has been synthesized using the monodispersive polystyrene (PS) microsphere as a self-sacrificing template. RGO/PS core-shell microsphere was prepared through - stacking interaction between PS microsphere and graphene oxide sheet, and then chemical reduction using hydrazine hydrate. MnO2/RGO/PS core-shell-shell microsphere was prepared through in situ chemical redox process between KMnO4 and benzyl alcohol-anchored RGO/PS. MnO2/RGO double-shelled hollow microsphere was obtained by etching PS microsphere from MnO2/RGO/PS using tetrahydrofuran. It had a pore diameter of 560-580 nm and layer thickness of 210-270 nm. Low charge transfer resistance of 0.3006 and total electrochemical impedance of 2.37 caused a high specific capacitance of 450.1 F g(-1) at 0.2 A g(-1). The capacitance retention of 81.7% after 1000 cycles indicated good cycling capability at 5 A g(-1). MnO2/RGO double-shelled hollow microsphere presented the promising application for supercapacitor electrode material.