Preparation of 3D Reduced Graphene Oxide/MnO2 Nanocomposites through a Vacuum-Impregnation Method and Their Electrochemical Capacitive Behavior

摘要

In this work, three-dimensional (3D) porous reduced graphene oxide (rGO) is prepared by means of a microwave-hydrothermal method, and then MnO2 is introduced in situ and anchored into the pores of the 3D-rGO through a novel vacuum-impregnation method to obtain the 3D-rGO/MnO2 nanocomposite. SEM images show the honeycomb structure of the 3D-rGO/MnO2, and MnO2 is tightly anchored on the surface and into the pores of 3D-rGO. 3D-rGO/MnO2 nanocomposite electrodes display excellent electrochemical capacitive behavior, owing to the synergetic effect between the porous 3D-rGO with high conductivity and MnO2 with high theoretical capacitance. The 3D-rGO/MnO2-5 sample, with an optimum MnO2 content of (53.1%), gives the highest specific capacitance (278.5 Fg(-1) at 1 Ag-1) and good rate capability. This sample also has remarkable cycling stability (93.5% capacitance retention after 10000 cycles). The 3D-rGO/MnO2 nanocomposite could be considered as a potential candidate for supercapacitor electrode materials.