In Situ Synthesis of Mesoporous NiMoO4 on Ball Milled Graphene for High Performance Supercapacitors

Abstract

Hydrothermal method is used to in situ synthesize mesoporous graphene@NiMoO4 nanocomposites as supercapacitor electrodes. NiMoO4 nanorods are formed on fresh graphene surface, while scattered NiMoO4 nanoparticles are obtained on the surface of ball milled graphene. graphene@NiMoO4 nanocomposites electrodes exhibit a higher electrochemical performance compared with a pure NiMoO4 electrode, and the ball milled graphene@NiMoO4 electrodes have the maximum specific capacitance of 2100 F g−1 at 1 A g−1 discharge current and maintains at least 92% of its initial capacitance after 5000 operational cycles. Such an enhanced supercapacitive performance originates from the mesoporous structure, more electroactive sites, large specific surface area, high electrical conductivity and synergistic effect between NiMoO4 and the graphene.