Scalable Synthesis of N–Doped Graphene–Oxide–Supported FeCo(OH)x Nanosheets for Efficient Co–Doped Fe3O4 Nanoparticle-Based Oxygen Reduction Reaction Electrocatalysis

An innovative intermediate-control-method for layered FeCo(OH) x enables selective formation of well-dispersed Fe 3 O 4 nanoparticles on NRGO, yielding spinel (Co)Fe 3 O 4 after 900 °C-calcination with supreme ORR activity and stability.