High quality double-walled carbon nanotubes (DWNTs) were synthesized by decomposition of methane over cobalt (Co) nanoparticles supported on porous MgO nanoparticles. The growth was significantly influenced by catalyst concentration and MgO type. Catalysts with 2.5–5 wt% Co loaded MgO (pore size: 4 nm) efficiently grow DWNTs with diameters of 2–4 nm, high graphitization, clean surfaces, and cle...

Transmission electron microscopy has been used to examine carbon isolated from the Allende meteorite. The structure of the carbon is rather disordered, consisting of curved and faceted graphene sheets with little large scale graphitization, and resembles that of a microporous carbon following high temperature heat treatment. Closed carbon nanoparticles, typically V2^10 nm in diameter are common...

This review summarizes the field of iron-catalyzed graphitization, which is a simple and flexible route to produce nanostructured graphitic carbons from wide range organic precursors.