Synthesis of graphene/Ru/NiO composites as highly active oxygen evolution reaction electrocatalysts.

[Display omitted] • Graphene/Ru/NiO composites are fabricated by a rapid ball milling approach. • OER activity of graphene/Ru/NiO composites is remarkably better than that of IrO 2. • OER activity of composites is attributed to collective contributions of Ru and NiO. Graphene nanoplates which are decorated uniformly with ruthenium (Ru) and nickel oxide (NiO) nanoparticles, are fabricated via ball milling of graphite, triphenylphosphine ruthenium chlorides and nickel chlorides. Electrochemical measurement results demonstrate that the resultant graphene/Ru/NiO composites deliver a lower overpotential of 240 mV at current density of 10 mA cm−2 and better durability for oxygen evolution reaction (OER) than the state-of-the-art iridium oxide catalysts. The superior OER performances of the graphene/Ru/NiO composites are attributed to collective contributions of Ru and NiO. [ABSTRACT FROM AUTHOR]