Activated carbon nanofibers (ACNF) were prepared from polyacrylonitrile (PAN)-based
nanofibers using CO2 activation methods with varying activation process times. The surface
and structural characteristics of the ACNF were observed by scanning electron microscopy
and X-ray diffraction, respectively. N2 adsorption isotherm characteristics at 77 K were confirmed
by Brunauer-Emmett-Teller and Dubinin-Radushkevich equations. As experimental
results, many holes or cavernous structures were found on the fiber surfaces after the CO2
activation as confirmed by scanning electron microscopy analysis. Specific surface areas and
pore volumes of the prepared ACNFs were enhanced within a range of 10 to 30 min of activation
times. Performance of the porous PAN-based nanofibers as an electrode for electrical
double layer capacitors was evaluated in terms of the activation conditions.