Enhancement of the methylene blue adsorption rate for ultramicroporous carbon fiber by addition of mesopores

Predominant mesopores were added to pitch-based activated carbon fiber (0.7 nm of average pore width) by Ca(NO3)2-impregnated chemical activation. The influence of the concentration of calcium nitrate solution, reactivation temperature and reactivation time on the mesopore development of ACF were examined. The development of mesopores in the reactivated ACF was evidenced by an explicit hysteresis of N2 adsorption isotherm at 77 K. The pore volume ratio of mesopores to micropores reached to 3–4. The addition of predominant mesopores to ACF enhanced the liquid phase adsorption rate of methylene blue by more than 10 times.