▎ 摘　　要

Transition metal oxides with nanostructures as electrode materials have become a popular topic for supercapacitors. A novel and simple approach was proposed to fabricate MnO2 nanoparticles on reduced graphene oxide (RGO). RGO was firstly deposited on nickel foam using electrophoretic deposition accompanied by subsequent thermal reduction. Then, MnO2 was deposited on RGO by electrodeposition with the applied potential of 0.6 V (vs. SCE) for 30 s. The morphology and structure of the deposits were analyzed in detail. Moreover, the electrochemical performance of MnO2 nanoparticle decorated graphene-based porous composite electrodes was investigated comprehensively. The results indicated that a large number of MnO2 nanoparticles with a diameter of approximately 5-50 nm were deposited on RGO that were independently separated by numerous fine gaps. The morphological characteristics endowed the electrode with a high specific area and short transfer path for electrons and active ions. The galvanostatic charge/discharge testing results indicated that the specific capacitance value of the electrode was calculated to be approximately 432 F.g(-1) at 1 A.g(-1). Approximately 55% of the initial specific capacitance was retained when the current density was sharply raised to 10 A.g(-1). MnO2/RGO also demonstrated an outstanding cycling stability where 97.5% of the initial specific capacitance was reserved when undergoing 500 cycles.