Improvement of NO gas sensing properties of polyaniline/MWCNT composite by photocatalytic effect of TiO2

Abstract

The highly sensitive and rapid NO gas sensor was prepared with polyaniline/TiO2/carbon nanotube composites. Aniline was polymerized on the surface of carbon nanotube (p-type semiconductor) with embedding TiO 2. The gas sensing property was measured by the changes of electrical resistance without or with UV irradiation to investigate the photodegradation of NO by TiO2. The photo-degraded products such as HNO2, NO2, and HNO3, which were adsorbed on the PANi-coated carbon nanotubes, resulted in the decreased electrical resistance in the p-type semiconductors of carbon nanotube and polyaniline. The advantages of TiO 2 photocatalyst in gas sensing were apparent in the improvement in both sensitivity and response rate. © 2013 Jumi Yun et al.