Growth of multiwalled carbon nanotubes from acetylene over in situ formed Co nanoparticles on MgO support

The performance of Co catalysts supported on MgO at different Co loading (10%–75%) for the formation of carbon nanotubes through acetylene decomposition at 600 ∘C with H2/C2H2 mixture for 1 h is investigated. The yield of MWNTs increases with an increase in Co loading (up to 50%). Starting from 1 g of catalyst precursor, about 8 g of MWNTs was obtained. The XRD patterns of catalyst precursor indicate the presence of cobalt in oxidic phase that eventually transformed into the catalytically active Co nanoparticles (12–18 nm) under the influence of acetylene and was responsible for the growth of coiled-like multi-walled CNTs as revealed by SEM and HRTEM images. It is suggested that bending in coil shaped MWNTs has the potential for functionalization for its biomedical applications.