Novel process to synthesize the well-size-controlled carbon nanotubes using Fe/TiO2 as catalyst by sol–gel method

The sol–gel method was used to grow nano-particles with the aid of iron catalyst, which was in advance uniformly spread over a silicon substrate by the spin coating technique. The well-aligned bamboo-like carbon nanotubes (CNTs) were grown on the Si wafer surface by microwave plasma chemical vapour deposition (MPCVD) method with the composition-controlled gaseous mixture of CH4, H2, and N2. By the HR-TEM technique, we have found that CNTs exhibit bamboo-like structure. Raman spectroscopy and XPS techniques were used to characterize as-grown bamboo-like CNTs. The results show that the base growing mode of CNTs predominates in sol–gel-prepared catalyst and nitrogen can enhance the formation of bamboo-like CNTs.