Activated carbon fibers via reductive carbonization of cellulosic biomass for adsorption of nonpolar volatile organic compounds

Abstract

Reductive carbonization of cellulosic fibers via nano-sized nickel catalyst in the presence of hydrogen was examined for production of activated carbon fibers (ACFs). The results showed that 99.5 % of oxygen originally presented in the biomass was removed as measured by using X-ray Photoelectron Spectroscopy (XPS), with over 63 % carbon in form of reductive species. Such reductive ACFs demonstrated high adsorption capacities for non-polar volatile organic compounds (VOCs). Particularly, the reductive ACFs absorbed benzene at a capacity that was 8 times higher than traditionally prepared carbon fibers. That can be attributed to both the reductive surface chemistry and morphology generated by the activity of the nanocatalysts. The unique network structure of the ACFs also provided a fine conductivity, that made it possible for efficient material regeneration via electrothermal desorption. The absorbed VOCs could be completely released within 1 min upon application of a moderate electrical current, and the regenerated materials could regain 100 % of its adsorption capacity even after repeated adsorption and desorption cycles. This work demonstrated for the first time the use of nanocatalyst-assisted reductive carbonization in manipulating surface properties of bio-based carbon materials, promising the production of a new class of carbon materials for industrial applications including air quality control, gas separation, and fuel storage.