Fe 2 O 3 particles encapsulated inside aligned CNx nanotubes

Aligned CNx nanotubes filled with Fe2O3 particles were synthesized through a single pyrolysis reaction of acetonitrile and Fe2O3/SiO2 catalyst at 900 °C under Ar2 flow. The number and spacing of the encapsulated Fe2O3 particles inside the CNx nanotubes were controlled by adjusting the amount and time of acetonitrile feeding. The chemical composition and atomic structure of the nanocapsulates were investigated using combined techniques of high-resolution electron microscopy, electron energy loss spectroscopy (EELS), and elemental mapping. It was found that the encapsulated particles were Fe2O3 particles and that the doped nitrogen atoms, which were mainly pyridine-like, bonded with two carbon atoms within the graphene sheets, giving rise to a π*-type peak at around 399 eV in EELS spectra.