▎ 摘　　要

The rational preparation of hierarchical MnO2/polypyrrole (PPy)/reduced graphene oxide (rGO) nanosheets in a sandwich structure is presented. By co-assembly of MnO2/GO and PPy/GO into layer-by-layer architecture and reduction of GO, ternary (MnO2, PPy)/rGO composites were first fabricated. The materials were fully characterized in terms of structure, morphology and electrochemical properties. The unique architecture offers the composites good capacitance by taking advantage of the strong synergistic effect of each component. A maximum specific capacitance as high as 404 F g(-1) was obtained for this composite electrode. And over 91% of the initial capacitance was retained after 5000 continuous cycles. The good electrochemical performance and long-term cycling stability make this approach attractive in developing multifunctional hierarchical composites for high-performance supercapacitors.