Giant cationic polyelectrolytes generated viaelectrochemical oxidation of single-walledcarbon nanotubes

摘要

Previously, reduced single-walled carbon nanotube anions have been used for effectiveprocessing and functionalization. Here we report individually separate and distinct (that is,discrete) single-walled carbon nanotube cations, directly generated from a pure anode using anon-aqueous electrochemical technique. Cyclic voltammetry provides evidence for thereversibility of this nanoion electrochemisty, and can be related to the complex electronicdensity of states of the single-walled carbon nanotubes. Fixed potentiostatic oxidation allowsspontaneous dissolution of nanotube cations (‘nanotubium’); Raman spectroscopy andtransmission electron microscopy show that sequential fractions are purified, separatingamorphous carbon and short, defective single-walled carbon nanotubes, initially. Thepreparation of nanotubium, in principle, enables a new family of nucleophilic graftingreactions for single-walled carbon nanotubes, exploited here, to assemble nanotubes onamine-modified Si surfaces. Other nanoparticle polyelectrolyte cations may be anticipated.