Plasma Modification of Activated Carbon Fibers for Adsorption of SO ₂

Viscose-based activated carbon fibers (VACFs) were treated by a dielectric-barrier discharge plasma under the feed gas of N ₂ . The surface functional groups of VACFs were modified to improve the adsorption and catalysis capacity for SO ₂ . The surface properties of the untreated and plasma-treated VACFs were diagnosed by SEM, BET, FTIR, and XPS, and the adsorption capacities of VACFs for SO ₂ were also compared and discussed. The results show that after the plasma treatment, the external surface of VACFs was etched and became rougher, while the surface area and the total pore volume decreased. FTIR and XPS revealed that nitrogen atoms were introduced onto the VACFs surface and the distribution of functional groups on the VACFs surface was changed remarkably. The adsorption characteristic of SO ₂ indicates that the plasma- treated VACFs have better adsorption capacity than the original VACFs due to the nitrogen functional groups and new functional groups formed in modification, which is beneficial to the adsorption of SO ₂ .