Preparation of gas sensor from pitch-based activated carbon fibers and its toxic gas sensing characteristics

Abstract

The electrode for gas sensor was prepared by using pitch-based activated carbon fibers and polyvinyl alcohol (PVA) to investigate the toxic gas sensing characteristics. The physicochemical properties of activated carbon fibers electrode for gas sensor were analyzed with SEM and BET. Toxic gases sensing property of the electrode was also identified by different toxic gases such as NH 3, NO and CO 2. The specific surface area of activated carbon fibers electrode for gas sensor was decreased by 33% owing to PVA used as a binder compared with the activated carbon fibers. However, its pore size distribution of the ACF electrode was not greatly influenced by PVA. The activated carbon fibers electrode for gas sensor responded to toxic gases by electron hopping unlike semiconductor based gas sensors. In this study, activated carbon fibers electrode was decreased to 7.5% in resistance for the NH3 gas of the 100 ppm concentration and its NH3 gas sensing property was confirmed the most excellent compared with other toxic gases. © 2014 The Korean Society of Industrial and Engineering Chemistry. All rights reserved.