•Three-dimensional graphene foam was synthesized by plasma-enhanced CVD.•The graphene foam exhibited a high electrical conductivity of 125S/cm.•The graphene foam showed a large surface area of 625.4cm2/g.•The prepared graphene foam/epoxy composites showed a high conductivity.•The derived graphene oxide foam showed an excellent absorption capability. A three-dimensional (3D), free-standing graphene foam was prepared by plasma-enhanced chemical vapor deposition on nickel-foam. The prepared graphene foam was found to consist of few-layered vertically-aligned graphene sheets with highly graphite structure. Owing to the 3D interconnected porous nanostructures, the graphene foam exhibited a high electrical conductivity of 125S/cm and a large surface area of 625.4cm2/g. For practical application, we prepared the graphene foam/epoxy composites showing a maximum conductivity of 196S/m at 2.5vol.% filler loading, and a rather low percolation threshold of 0.18vol.%. Furthermore, the derived graphene oxide foam exhibited an excellent absorption capability (177.6mg/g for As(V), 399.3mg/g for Pb(II)) and recyclability (above 90% removal efficiency after five cycles) for the removal of heavy metal ions. The present study reveals that the multifunctional graphene foam may broaden the graphene-based materials for the applications in electrically conductive composites and environmental cleanup.