Oxygen Reduction and Evolution in an Ionic Liquid Electrocatalyzed by a Highly Active Au Nanoparticles/Graphene Hybrid

A hybrid of reduced graphene oxide (RGO) sheets and gold nanoparticles (AuNPs), which mainly feature Au(111) planes and have an average diameter of 8 nm, has been prepared by using a facile approach. The RGO/AuNPs hybrid exhibits high bifunctional electrocatalytic activity toward the oxygen reduction reaction (ORR) as well as the oxygen evolution reaction (OER) in room-temperature ionic liquid (RTIL). Compared with the performance of a commercial Pt/C material, a higher ORR current density as well as a much better reversibility of ORR/OER has been obtained on RGO/AuNPs, suggesting that this novel hybrid material could be employed as a promising catalyst for the development of IL-based rechargeable metal-air batteries.