A convenient, general synthesis of carbide nanofibres via templated reactions on carbon nanotubes in molten salt media

Carbide nanofibres were synthesized by reaction of various transition metals with carbon nanotubes using a molten LiCl–KCl–KF salt system as a reaction medium. Metal sources included titanium, zirconium, hafnium, vanadium, niobium and tantalum powders. Multi-walled carbon nanotubes were used both as a carbon source and also as a template for the preparation of titanium carbide, zirconium carbide, hafnium carbide, vanadium carbide, niobium carbide and tantalum carbide nanofibres. Generally, the carbide products were characterized by scanning electron microscopy, transmission electron microscopy, selected-area electron diffraction and electron energy loss spectroscopy. The polycrystalline carbide nanofibres produced in these reactions have a similar morphology to that of their multi-walled carbon nanotube precursors. However, when using titanium mixed with titanium dioxide as a titanium source, both polycrystalline and straight, single crystal titanium carbide nanofibres are formed.