Copper nickel@reduced graphene oxide nanocomposite as bifunctional electro-catalyst for excellent oxygen evolution and oxygen reduction reactions

Herein, we demonstrate that copper nickel (CuNi)@reduced graphene oxide (RGO) nanocomposite (NC) is an excellent bifunctional electro-catalyst to oxygen evolution (OER) and oxygen reduction reactions (ORR). CuNi@RGO-NC shows impressive electro-catalytic activity with fairly low onset over-potentials for OER (similar to 135 mV) and ORR (similar to 60 mV) in alkaline medium. Tafel slopes of CuNi@RGO-NC were found to be similar to 182 and similar to 86 mV/dec for OER and ORR, respectively. CuNi@RGO-NC exhibits better retention rate (88%) than CuNi nanoparticles (NPs) and also reveals the comparable OER/ORR activities with expensive electro-catalysts (20% Pt/C). (C) 2019 Elsevier B.V. All rights reserved.