High capacity supercapacitor material based on reduced graphene oxide loading mesoporpus murdochite-type Ni6MnO8 nanospheres

•Mesoporous Ni6MnO8 nanospheres (NMN) with high specific surface area and unimodal pore diameter distribution were prepared.•NMN was uniformly dispersed on reduced graphene oxide sheets to fabricate RGO-NMN composite.•Both NMN and RGO-NMN electrodes showed a high specific capacitance and long cycle life.

Mesoporous materials often deliver a series of attractive properties for low-cost and environmentally-friendly energy storage/conversion technologies. Based on this, we prepared mesoporous murdochite-type Ni6MnO8 nanospheres (NMN) with a uniform morphology by using a template route. Then as-prepared NMN were loaded uniformly on reduced graphene oxide (RGO) sheets via electrostatic interaction to fabricate RGO-NMN composite (RGO-NMN), which combines the advantages of both RGO such as double-layer capacity and NMN such as high pseudocapacitity. By the aid of a nanosized mesoporous silica template, NMN and RGO-NMN display a large specific surface areas and concentrated pore diameter distribution. The large surface area and abundant pores can provide a promising route for easy access of electrolyte in energy storage electrodes and favor the availability of Faradic reaction in electroactive sites greatly. Indeed, following electrochemical analysis uncovered a remarkable value of specific capacitance (862.5 F g−1 and 498.3 F g−1 at 0.5 A g−1 for RGO-NMN and NMN) and a predominant long-term stability with slight decays less than 10% after 9000 cycling test in both NMN and RGO-NMN electrodes.

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