In this study, activated carbon fibers (ACFs), onto which silver (Ag) nanoparticles have been introduced by an electroplating technique, were used to remove NO. Surface properties of the ACFs were determined by X-ray diffraction and scanning electron microscopy. N-2 adsorption isotherms at 77 K were investigated by BET and t-plot methods to characterize the specific surface areas and pore volumes, and NO removal efficiency was confirmed by a gas chromatographic technique. As for the experimental results, Ag content on the ACFs increased with plating time. However, adsorption properties such as the BET specific surface area and the total pore volume were somewhat decreased in the presence of Ag nanoparticles. NO removal efficiency of all Ag-ACFs was higher than that of untreated ACFs and increased with Ag content. However, a decrease in the extent of NO removal was shown in the excessively plated ACFs, which might be associated with the blocking of the micropores in the carbon; therefore, an optimal Ag content needs to exist in the presence of initially well-developed micropores to lead to an increase in the efficient NO removal ability of the ACE (C) 2004 Published by Elsevier Inc.