Purification and opening of carbon nanotubes via bromination

The purification and opening of carbon nanotubes via bromination is reported. Refluxing raw cathodic soot containing a mixture of nanotubes, nanoparticles, and amorphous carbon in liquid bromine, followed by oxidation in air, is shown to yield 10–20; w/w pure and opened nanotubes. The role of bromine in the purification steps is discussed, based on the results of transmission electron microscopy, temperature programmed oxidation, X‐ray diffraction, and X‐ray photoelectron spectroscopy investigations.