The development of a ‘process map’ for the growth of carbon nanomaterials from ferrocene by injection CVD†
Ferrocene was used as a catalyst in a hydrocarbon solution to carry out injection chemical vapour deposition (CVD) growth of carbon nanomaterials in a horizontal tube furnace. The presence and quality of various carbon materials was determined using Raman spectroscopy, thermogravimetric analysis, and electron microscopy. Products ranged from amorphous carbon (a-C), multi walled carbon nanotubes (MWNTs) and vapour grown fibers (VGFs). Catalyst concentration, growth temperature, injection rate, carrier gas flow rate, and the choice of hydrocarbon were found to influence the product outcome. Slower injection rates gave higher isolated yield. High catalyst concentrations were found to produce less pure carbon materials with iron oxides impurities. Higher temperatures were favourable to nanotube formation. The use of benzene was found to increase yield compared with the other hydrocarbons. In this work we developed a process map to chart the various carbon nanomaterial allotropes that were created according to reaction parameters.