Facile and Large Scale Fabrication of Thick Walled Carbon Nanotubes by Using Waste Tire Pyrolysis Oil as Carbon Feedstock

Thick-walled carbon nanotubes (TWCNTs) have been successfully grown on silicon substrate under argon stream by a simple spray pyrolysis method using waste tire pyrolysis oil (TPO) as carbon feedstock and ferrocene as a catalyst. The structural morphology of as-grown TWCNTs have been characterized by using X-Ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), Raman spectroscopy and thermogravimetric analysis (TGA). SEM and TEM studies reveal that the as-grown TWCNTs have different lengths in the wide range from few micrometers to 100 micrometers, the internal diameter of the hollow cylindrical channel is in the range of 50-100 nm and the wall thickness is in the range of 100-300 nm. TWCNTs possess a different structural morphology of carbon tubes with very thick graphitic walls as compared with single or multi-walled carbon nanotubes. XRD and TGA results demonstrate the presence of crystalline graphitized structure with high purity of ca. 95% mass fraction. This study explored the potential use of TPO derived from waste tire as a low-cost and highly available carbon feedstock which could be an effective starting precursor for the large scale production of TWCNTs with high purity for diverse applications in microelectronic devices.