Active forms of oxygen as agents for electrochemical functionalization of SWCNTs

The electrochemical method of grafting functional groups onto single-walled nanotube surface by active oxygen-containing intermediates generated by electrolysis of water in neutral and alkaline aqueous solutions is proposed. As a result of electrolysis the relative concentrations of oxygen-containing functional groups in solutions of sodium sulfate and potassium hydroxide achieve ∼26 and ∼12 at.% correspondingly, whereas specific capacities values of electrochemically treated SWCNT electrodes are ∼80 and 2–4 F/g, respectively. This distinction between the results of electrochemical treatment is supposed to be determined by a different nature of intermediates generated on the surface of nanotubes in neutral and alkaline solutions at anodic region of potentials. In the first case, the main oxidizing agents are OH-radicals; in the latter case – О⁻ ions and their oxidizing ability is essentially lower.