| 초록 |
The gas sensor electrodes were prepared by activated carbon fibers (ACFs) and polyvinyl alcohol (PVA) to investigate the toxic gas sensing characteristics. The ACFs-based gas sensor electrode was prepared by ACF (pitch-based ACFs, Ad'all-20, osaka gas, Japan) and 20 wt% PVA solution (Mw 22000, junsei, Japan) with weight ratio (ACF : PVA solution = 1 : 1) at 300 ℃ for 1h. The specific surface area of ACFs-based gas sensor electrode was decreased by 33% owing to using the PVA compared with pure ACFs. The resistance of ACFs-based gas sensor electrode was decreased 7.5% at NH3 gas (reducing gas). CO2 and NO gas (acceptor gas) also were decreased 0.8, 1.9%, respectively. The gas sensor electrode did not show the semiconductor’s characteristics and then the change of resistance depended on the adsorption of gas molecules in pores. Therefore, ACFs-based gas sensor electrode would sense the toxic gas by adsorption (electron hopping effects) unlike semiconductor based gas sensor. |
