Activated carbon fiber (ACF) surfaces are modified using an electron beam under different aqueous solutions to improve the NO gas sensitivity of a gas sensor based on ACFs. The oxygen functional group on the ACF surface is changed, resulting in an increase of the number of non-carbonyl (-C-O-C-) groups from 32.5% for pristine ACFs to 39.53% and 41.75% for ACFs treated with hydrogen peroxide and potassium hydroxide solutions, respectively. We discover that the NO gas sensitivity of the gas sensor fabricated using the modified ACFs as an electrode material is increased, although the specific surface area of the ACFs is decreased because of the recovery of their crystal structure. This is attributed to the static electric interaction between NO gas and the non-carbonyl groups introduced onto the ACF surfaces.

• Mi-Seon Park(Department of Chemical Engineering and Applied Chemistry, Chungnam National University, Daejeon 34134, Korea)
• Sangmin Lee(Department of Chemical Engineering and Applied Chemistry, Chungnam National University, Daejeon 34134, Korea)
• Min-Jung Jung(Department of Chemical Engineering and Applied Chemistry, Chungnam National University, Daejeon 34134, Korea)
• Hyeong Gi Kim(Korea Fire Safety Association (KFSA), Daejeon, 34426, Korea) The authors have contributed equally in discussions of the work, performing the experiments, and writing the paper. Corresponding Author
• Young-Seak Lee(Department of Chemical Engineering and Applied Chemistry, Chungnam National University, Daejeon 34134, Korea) The authors have contributed equally in discussions of the work, performing the experiments, and writing the paper. Corresponding Author