Catalytic CVD synthesis of double-walled carbon nanotubes with a narrow distribution of diameters over Fe–Co/MgO catalyst

Double-walled carbon nanotubes with a narrow distribution of diameters have been synthesized by catalytic CVD of methane over Fe–Co/MgO catalyst. The as-synthesized double-walled carbon nanotubes were characterized by scanning electron microscopy, high-resolution transmission electron microscopy and Raman spectroscopy. The obtained double-walled carbon nanotubes have an inner and an outer diameter of 0.6–1.2 and 1.3–2 nm, respectively. Raman analysis and high-resolution transmission electron microscopy observation indicated that the prepared double-walled carbon nanotubes were of high quality.