The self-assembly of shape controlled functionalized graphene–MnO2 composites for application as supercapacitors

Abstract

Graphene–MnO₂ nanocomposites with different morphologies were obtained by a facile self-assembly method. The formation mechanism of graphene–MnO₂ composites with different shapes of MnO₂ is discussed in detail. Nanostructured MnO₂ with different morphologies was distributed on the surface of graphene uniformly. The prepared graphene–MnO₂ composites could be used as electrode materials for supercapacitors. The graphene–MnO₂ (flowerlike nanospheres) composite (405 F g⁻¹) exhibited better capacitive performance than that of the graphene–MnO₂ (nanowires) composite (318 F g⁻¹) at a current density of 1.0 A g⁻¹. The synergistic effect of graphene and MnO₂ endowed the composite with high electrochemical capacitance. Moreover, the graphene–MnO₂ (flowerlike nanospheres) composite showed a fast charge–discharge process and high cyclic stability.