Comparative study on homogeneity, filling ratio and purity of iron filled multiwalled carbon nanostructures

Iron filled carbon nanotubes have been widely used for numerous applications due to their remarkable magnetic and structural properties. One very important example is the biomedical application, where iron filled multiwalled carbon nanotubes (Fe-MWCNT) can be used in anticancer therapies, acting as local nano-heaters, at the cellular level. Regarding this aim the systematic study of the Fe-MWCNT preparation was required. Therefore, in this contribution a chemical vapour deposition (CVD) process was employed to perform a comparative study on Fe-MWCNT synthesis using two carbon feedstock (cyclohexane and ethanol), and different catalyst mixtures. The homogeneity, filling ratio, and purity of the samples were analysed, and the optimal conditions for the bulk sample preparation were achieved. The samples were characterised concerning their quality, diameter range, number of walls, and amount of iron encapsulated in the nanotubes cavity. The characterisation was performed using Raman spectroscopy, transmission electron microscopy (TEM), and thermogravimetric analysis (TGA).