Abstract
The wide range of oxygen-containing functional groups on the basal planes and edges of graphene oxide (GO) facilitate the anchoring of active metal ions on its surface. Previously, we have shown that these active centers allow the in situ crystallization of cyano-bridged Ni-based coordination polymers (Ni-CP) as nanoflakes on the surface of GO sheets (Angew. Chem. Int. Ed., 2016, 55, 8426). Here, in this work, by extending our previous concept, we demonstrate that Ni-CP-coated GO sheets can be made to self-assemble to form various multi-layered hybrid structures (Ni-CP/GO) by controlling the composition ratios. Ni3C/rGO with the original morphology was successfully prepared by converting the Ni-CP to Ni3C in the space between the graphene sheets by thermal treatment in an inert atmosphere. The electrochemical analyses reveal that the optimized Ni3C/rGO hybrid exhibits superior electrocatalytic performance for the oxygen reduction reaction (ORR) with good durability and stability.