Reduced graphene oxide–nickel oxide composite as high performance electrode materials for supercapacitors

Reduced graphene oxide and NiO composite is prepared by homogeneous coprecipitation and subsequent annealing. Characterizations show that NiO particles have a nanosheet-based microsphere structure and anchor uniformly on the surface of reduced graphene oxide platelets. The RG-O/NiO-based supercapacitors exhibit high specific capacitance of 770 F g−1, and enhanced rate capability. It is found that the electrochemical performance can be enhanced by anchoring NiO particles on the surface of RG-O platelets in the RG-O/NiO composite. This method provides a facile and straightforward approach to distribute NiO nanoparticles onto the surface of RG-O sheets and can be extended to the preparation of other RG-O/metal oxides composite for electrochemical energy storage.

► RG-O/NiO is obtained by a simple method of homogeneous coprecipitation followed by annealing. ► NiO has the morphology of nanosheet-based microspheres which are uniformly distributed on the surface of RG-O platelets. ► As an electrode of supercapacitors, the RG-O/NiO has 770 F g−1 specific capacitance which is much higher than pure NiO or NiO/carbonaceous materials previously reported in the literatures. ► The synthesis method of RG-O/NiO can be extended to the preparation of the RG-O/metal oxide composite for electrochemical energy storage.