Synthesis of novel Y-junction hollow carbon nanotrees

A simple catalyst-dwindling route without additional templates has been developed, for the first time, to synthesize novel Y-junction hollow carbon nanotrees in a high-yield of 90% by the reaction of ferrocene with 1,2-dichlorobenzene at 180 °C. The nanotrees have an average length about 5 μm, an average external trunk diameter of about 500 nm, branch diameters ranging from 70 to 100 nm, and wall thickness ranging from 24 to 30 nm. Unlike traditional carbon nanotubes, these nanotrees have close-ended branches but open-ended roots. X-ray powder diffraction, field emission scanning electron microscopy, transmission electron microscope, high-resolution transmission electron microscopy, electron diffraction, X-ray photoelectron spectroscopy and Raman spectroscopy were used to characterize the products. It is also found that proper reaction temperatures and appropriate proportion of ferrocene and 1,2-dichlorobenzene play important roles in this route. The formation mechanism of treelike carbon nanotubes was simply proposed.