Lignin-based multiwall carbon nanotubes

Carbon particles were produced by carbonization of perfectly spherical, sub-micron beads obtained from Kraft lignin. While the bulk of the particles consisted of carbon with only moderate structural order, high-resolution transmission electron microscopy revealed the presence of highly ordered multilayered carbon structures adhering to the surface of the carbon spheres. Besides irregularly shaped multiwall carbon, well-defined multiwall carbon nanotubes were identified. Energy dispersive x-ray analysis hints at a catalytic action of metallic impurities present in lignin in the synthesis of these lignin-based carbon nanostructures. Lignin-based multiwall carbon nanotubes are considered of high interest with regard to providing bio-based alternatives for fossil-based high-performance materials.