In-situ growth of Fe nanoparticles encapsulated by carbon onions with controllable thickness on graphene nanoribbon-reinforced graphene

Abstract Introduction of magnetism in large-area monolayer graphene has captured much attention in the graphene community, owing to the potential applications in transistors, magnetic memory, spintronic devices, and so on. Here, we use graphene nanoribbons (GNRs) as reinforcing rebar to in situ reinforce large-area graphene, where the edges of graphene nanoribbons are found to be seamlessly welded with graphene sheet. Based on the GNR-reinforced graphene, Fe nanoparticles encapsulated by carbon nano-onions (CNOs) with controllable shell thickness are in situ grown on the surface to introduce efficient ferromagnetic phase to graphene by a facile and scalable method. When core-shell Fe@CNOs with thick shells are anchored, the hybrid film shows a strong p-doping electric behavior and an intriguing ferromagnetic property with remarkable remanence and coercivity in applied magnetic fields. The in situ growth of nanoscale Fe@CNOs on large-area GNR reinforced graphene will provide an additional avenue for the application of graphene-based films in flexible and transparent spintronic or magnetic electronics.