Effect of surface treatment by O3 and chemical activation by alkali metal on the performance of ACFs on adsorption and desorption of BTX gases

Abstract

In order to investigate the adsorption characteristics of activated carbon fibers (ACFs) with improved surface morphologies towards volatile organic compounds (VOCs), a commercial low-grade ACF was surface modified by successive surface treatment (ST) and chemical activation (CA) process. O3 was used as an ST agent for the formation of oxygen-containing functional groups on the carbon matrix of ACFs. CA was carried out after ST, using a KOH solution. After the successive ST-CA process, Brunauer-Emmett-Teller (BET) surface area and average pore diameter of ACFs were increased from 1483 m2 /g to 2743 m2 /g and enlarged from 1.931 nm to 2.512 nm, respectively. The successive ST-CA process also resulted in the adsorption capacities of benzene, toluene, and xylene of the ACFs to increase from 0.22 g−Ben. /g−ACFs, 0.18 g−Tol. /g−ACFs, and 0.19 g−Xyl /g−ACFs up to 0.37 g−Ben. /g−ACFs, 0.35 g−Tol. /g−ACFs, and 0.38 g−Xyl /g−ACFs, respectively.