In this study, a CuO support was successfully introduced onto an activated carbon fiber (ACF) surface by sputtering and was chemically formed by growth and aggregation to improve the active sites for high efficiency SO2 gas adsorption. The gas adsorption mechanism was studied based on the pore structure, gas adsorption behaviour and electrical resistance of the ACF during gas adsorption. This process improved two steps of the adsorption mechanism. First, the pore structure significantly influenced the gas adsorption properties. Second, the CuO support attracted the target gas to the surface of the ACFs through copper metal groups. The adsorption properties for SO2 gas were improved by the electrical resistance of the ACFs through the electron hopping effect of the adsorbed polarized SO2 molecules. (C) 2017 Published by Elsevier B.V.