The effect of carbon microfiber substrate pretreatment on the growth of carbon nanomaterials

The floating catalyst method was used to obtain carbon nanotubes, carbon submicrotubes and other carbon nanomaterials by changing the pretreatment conditions of carbon microfiber substrate. The morphology and microstructure of the obtained products were characterized by field emission scanning electron microscopy, high-resolution transmission electron microscopy and Raman spectroscopy. The results showed that on untreated carbon microfiber surface, only some carbon particles and several carbon nanotubes were deposited. However, after carbon microfibers were boiled in the solution of H2SO4/HNO3 and were immersed in the solutions of Fe(NO3)3/xylene, Fe(NO3)3/acetone, ferrocene/acetone and Fe(NO3)3/ferrocene/acetone, the obtained products were a high-density carbon nanotubes, carbon nanotubes with many carbon particles, carbon submicrotubes and a mixture of carbon nanomaterial, respectively. Thus the pretreatment of the carbon microfiber substrate greatly influenced the morphology and microstructure of the synthesized products.