Abstract: Carbon nanotubes can be synthesized via the detonation of the mixture of picric acid, cobalt acetate and phenanthrene at an appropriate molar ratio in a sealed stainless steel pressure vessel. TEM result shows that the carbon nanotubes present an appearance of entangled morphologies with outer diameters of 20-40 nm. The average lengths of the nanotubes between the two entangled points range from several to 40 μm. HRTEM result reveals the multi-wall structure of the obtained nanotubes. The in situ formed cobalt catalysts validated by XRD and TEM are crucial to the carbon nanotubes formation during the detonation. The abundance of nanotubes depends critically on the loading density of picric acid, under the experiment conditions and a high loading density is preferable to the preparation of nanotubes-rich products. Under an optimal condition(0.2 g/cm³ loading density), the purity of as-synthesized nanotubes can be up to 70%, as confirmed by the combination of investigations of TEM and TG.

Key words: Detonation, Catalysis, Multi-wall carbon nanotubes, Transmission electron microscopy, X-ray diffraction