Facile synthesis of three-dimensional graphene/nickel oxide nanoparticles composites for high performance supercapacitor electrodes

•The 3D porous graphene/NiO nanoparticle composites (3D-RGNi) are synthesized by a facile method.•The porous reduced graphene decorated with NiO nanoparticles was fabricated from thermal treatment.•The prepared 3D-RGNi possess the high electrochemically active surface area.•The 3D-RGNi exhibits a high capacitance of 1328 F g−1 with an excellent cycling stability.

This study presents a simple and facile method for preparing three-dimensional (3D) porous reduced graphene oxide (rGO) and NiO nanoparticles composites (3D-RGNi) as high performance supercapacitor electrodes. The 3D porous graphene framework is first produced by the self-assembly of poly(methyl methacrylate) (PMMA) particles and graphene oxide (GO), followed the adsorption of Ni precursor on GO. High-temperature treatment is simultaneously carried out to fabricate the 3D porous structured rGO decorated with NiO nanoparticles. The as-synthesized 3D-RGNi electrode exhibits a high specific capacitance of 1328 F g−1 at a current density of 1 A g−1 and an excellent cycling stability with 87% retention of the capacitance after 2000 cycles of galvanostatic charge–discharge. These high capacitance performances are attributed to the synergistic effects from the incorporation of the rGO network and NiO nanoparticles, and the highly porous structure of 3D-RGNi. Hence, it is expected that 3D-RGNi might serve as a promising materials for electrochemical energy storage applications.

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