Development of nanostructured polyaniline-titanium dioxide gas sensors for ammonia recognition

The performance at room temperature of nanostructured polyaniline (PANi)titanium dioxide (TiO2) ammonia gas sensors was investigated. The PANiTiO2 thin-film sensors were fabricated with a spin-coating method on glass substrates. PANiTiO2 (050%) sensor films were characterized for their structural, morphological, optical, and various gas-sensing properties. The structural analysis showed the formation of nanocrystalline TiO2, whereas PANi exhibited an amorphous nature. Morphological analysis of the PANiTiO2 nanocomposites film revealed a uniform distribution of TiO2 nanoparticles in the PANi matrix. The absorption peaks in the Fourier transform infrared spectra and ultravioletvisible spectra of the PANiTiO2 composite film were found to shift to higher wave numbers compared to those observed in pure PANi. The observed shifts were attributed to the interaction between the TiO2 particles and the PANi molecular chains. The gas-sensing properties showed that the sensors exhibited selectivity to ammonia (NH3) at room temperature. (c) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012