Self-protected nickel–graphene hybrid low density 3D scaffolds

Abstract

The development of low density metallic foams is highly intriguing for various applications. Moreover, the synthesis of hierarchical 3-dimensional structures of graphene is also receiving tremendous attention in recent days because of their unique electrical, thermal, mechanical and chemical properties. Here, we demonstrate a novel method for the bulk production of graphene protected, freestanding, low density (0.03–0.15 g per cc) metallic nickel (Ni) foam (NiG) by a simple polyol assisted chemical route. This hybrid NiG foam is synthesized in air, and during its synthesis, Ni is protected by graphene from its oxidation. These magnetic scaffolds can be used for various energy and environmental applications, and also can be structurally reinforced with other polymers. Polymethyl methacrylate (PMMA) is infiltrated into the Ni/NiG foams and the subsequent annealing of Ni/PMMA composite foam in Ar–H₂ atmosphere at 900 °C leads to the formation of large area graphene by the graphitisation of PMMA on Ni. This large area graphene is separated and studied for its properties.