Carbon and nitrogen-doped carbon(CNx) nanotubes were synthesized by detonation-assisted chemical vapor deposition with CNTs as seeds and paraffin as the carbon source and melamine as the carbon/nitrogen source.Transmission electron microscopy and electron energy loss spectroscopy were performed to characterize both materials.CNx nanotubes exhibited a compartmentalized bamboo-like structure and contained a high concentration of nitrogen(17.3 at %),while the new pure CNTs had hollow cores.The role of the original CNTs added to the raw materials could be ascribed to their curvature and open tip edges,which adsorbed Cn/CN species and assembled them into carbon and CNx nanotubes.