Improvement of NO Gas Sensing Properties of Polyaniline/MWCNT Composite by Photocatalytic Effect of TiO 2

The highly sensitive and rapid NO gas sensor was prepared with polyaniline/TiO 2 /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 TiO 2 . The photo‐degraded products such as HNO 2 , NO 2 , and HNO 3 , 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.