Non-aqueous synthesis of ultrasmall NiO nanoparticle-intercalated graphene composite as active electrode material for supercapacitors

•RGO/NiO nanocomposites were prepared using tert-butanol via ultrasonication process.•Ultrasmall nickel oxide nanoparticles, ca. 8 nm in size, were deposited on the graphene sheets.•The resulting RGO/NiO electrode exhibited a high capacitance of 689 F g−1 at 0.8 A g−1.

With the vast exploration of the applications of graphene, researchers are assessing different methods for fabricating graphene-based electrode material with high capacitance but low material and energy costs. In this study, reduced graphene oxide/nickel oxide (RGO/NiO) nanocomposites were prepared using a non-aqueous solvent-based method followed by calcination. Nickel acetate tetrahydrate and tert-butanol were used as the precursor and solvent, respectively. Ultrasmall nickel oxide nanoparticles, ca. 8.0 nm in size, were deposited on the surface of the graphene sheets simultaneously with the partial reduction of graphene oxide. The resulting RGO/NiO electrode exhibited a high capacitance of 689 F g−1 at a current density of 0.8 A g−1. After 1500 cycles, the specific retention and the coulombic efficiency yielded to 86.34% and 96.39%, respectively, which supports the viability of this composite as an alternative activated material with high electrochemical performance.

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