Fluidized-bed CVD synthesis of carbon nanotubes on Fe{sub}2O{sub}3/MgO

摘要

Carbon nanotubes were synthesised by the fluidised-bed CVD synthesis of iso-pentane (C{sub}5H{sub}12) and acetylene (C{sub}2H{sub}2) on a magnesium oxide (MgO) powder impregnated with an iron nitrate (Fe(NO{sub}3){sub}3·9H{sub}20) solution. Large quantities of nanotubes can be produced by this technique due to the high specific surface area (100 m{sup}2 g{sup}(-1)) of the precursor powder and the good convection in the fluidised bed. The main advantage of MgO is its high solubility in hydrochloric acid. Different synthesis parameters such as the iron content in the precursor (2.5-15%), the synthesis temperature (450-850 ℃) and the synthesis time (0.5-40 mm) were investigated. The synthesised material was characterised by scanning- and transmission electron microscopy, X-ray diffraction, Raman spectroscopy and BET. The purified samples consist of mostly single- and multi-walled carbon nanotubes.