Template-free, facile synthesis of core-shell carbon networks

In this study, we present a fast and easy, template-free chemical vapour deposition approach to synthesize a highly graphitic network consisting of entangled carbon nanotubes (CNTs) as a core and a pyrolytic graphite (PyG) coating as a shell around the CNTs forming a cohering sponge. The network height and density is tailorable by variation in the process parameters. Here, the height ranges between few micrometers and several millimeters, whereas the density ranges varies from 18 to 47 mg/cm(3). In addition, we describe the evolution of the aerogel morphology by increasing synthesis time and conclude that the growth is determined by a simultaneous catalytic growth of CNTs and a pyrolytic deposition of graphite on the CNTs. First studies of electrical and thermal properties of the network and its epoxy composite revealed maximum conductivities of 1.7 +/- 0.1 S/m and 0.58 +/- 0.13 W/mK, respectively.