Effects of different carbon precursors on synthesis of multiwall carbon nanotubes: Purification and Functionalization

► CNTs was synthesized using cyclohexanol and xylene. ► Cyclohexanol reduces amorphous carbon and catalyst deactivation. ► Cyclohexanol can enhance crystallinity and growth of CNTs. ► HNO3 8 M treatment removes encapsulated catalyst particles from CNTs. ► Among other acid treatments, HNO3 8 M prevents CNTs damaging.