One step simultaneous electrochemical synthesis of NiO/multilayer graphene nanocomposite as an electrode material for high performance supercapacitors

A NiO/graphene nanocomposite has been prepared via one step electrochemical synthesis using simultaneous pulse alternating current dispersion of both Ni electrode and an electrode of thermally expanded graphite. Electron microscopy and Raman spectroscopy data reveals that the composite consists of graphene sheets with 2–5 layers having 0.5–2 μm size as well as NiO sheets with 200–250 nm dimensions comprising NiO nanoparticles of ∼3.6 nm diameter. The electrochemical capacitance of the nanocomposite is 825 F g−1, with retaining 89% of the initial value after 1000 operation cycles.