Elsevier, Chemical Physics Letters, 1-2(361), p. 35-41
DOI: 10.1016/s0009-2614(02)00684-x
Full text: Unavailable
Microporosity of pure multi-walled carbon nanotubes (MWNTs) has been highly developed using chemical KOH activation. Depending on the nanotubular material, the burn-off ranged from 20% to 45% after the activation process. At least twofold increase of surface area has been obtained with maximum values of ca. 1050m2/g for KOH/C ratio of 4:1. The activated material still possesses a nanotubular morphology with many defects on the outer walls that give a significant increase of micropore volume, while keeping a noticeable mesoporosity. Such activated MWNTs have been used as electrode material for supercapacitors in alkaline, acidic and aprotic medium. Enhanced values of capacitance were always observed after activation: in some cases it increased almost seven times from 15 F/g (for non-activated nanotubes) to 90 F/g (after chemical activation).