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

摘要

The performance at room temperature of nanostructured polyaniline (PANi)-titanium dioxide (TiO _2) ammonia gas sensors was investigated. The PANi-TiO _2 thin-film sensors were fabricated with a spin-coating method on glass substrates. PANi-TiO _2 (0-50%) sensor films were characterized for their structural, morphological, optical, and various gas-sensing properties. The structural analysis showed the formation of nanocrystalline TiO _2, whereas PANi exhibited an amorphous nature. Morphological analysis of the PANi-TiO _2 nanocomposites film revealed a uniform distribution of TiO _2 nanoparticles in the PANi matrix. The absorption peaks in the Fourier transform infrared spectra and ultraviolet-visible spectra of the PANi-TiO _2 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 TiO _2 particles and the PANi molecular chains. The gas-sensing properties showed that the sensors exhibited selectivity to ammonia (NH _3) at room temperature.