Comparative studies of porous carbon nanofibers by various activation methods

Abstract

In this study, activated carbons nanofibers (ACNFs) were prepared from polyacrylonitrile-based nanofibers by physical (<TEX>$H_2O$</TEX> and <TEX>$CO_2$</TEX>) and chemical (KOH) activation. The surface and structural characteristics of the porous carbon were observed by scanning electron microscopy and X-ray diffraction, respectively. Pore characteristics were investigated by <TEX>$N_2$</TEX>/77K adsorption isotherms. The specific surface area of the physically ACNFs was increased up to <TEX>$2400m^2/g$</TEX> and the ACNFs were found to be mainly composed of micropore structures. Chemical activation using KOH produced ACNFs with high specific surface area (up to <TEX>$2500m^2/g$</TEX>), and the micropores were mainly found in the ACNFs. The physically and chemically ACNFs showed both mainly type I from the International Union of Pure and Applied Chemistry classification.