Three-dimensional flexible and conductive interconnected graphene networks grown by chemical vapour deposition

Integration of individual two-dimensional graphene sheets(1-3) into macroscopic structures is essential for the application of graphene. A series of graphene-based composites(4-6) and macroscopic structures(7-11) have been recently fabricated using chemically derived graphene sheets. However, these composites and structures suffer from poor electrical conductivity because of the low quality and/or high inter-sheet junction contact resistance of the chemically derived graphene sheets. Here we report the direct synthesis of three-dimensional foam-like graphene macrostructures, which we call graphene foams (GFs), by template-directed chemical vapour deposition. A GF consists of an interconnected flexible network of graphene as the fast transport channel of charge carriers for high electrical conductivity. Even with a GF loading as low as similar to 0.5 wt%, GF/poly(dimethyl siloxane) composites show a very high electrical conductivity of similar to 10 S cm(-1), which is similar to 6 orders of magnitude higher than chemically derived graphene-based composites(4). Using this unique network structure and the outstanding electrical and mechanical properties of GFs, as an example, we demonstrate the great potential of GF/poly(dimethyl siloxane) composites for flexible, foldable and stretchable conductors(12).