Room Temperature Ammonia Gas Sensor Based on Polyaniline-TiO$_{2}$ Nanocomposite

In the present work, we report on the performance of room temperature ammonia gas sensor based on polyaniline-titanium dioxide (PANi-TiO ₂ ) nanocomposite. The nanocomposite was fabricated using the spin coating method on glass substrates. PANi-TiO ₂ (0%-50%) nanocomposite films were characterized for their structural as well as surface morphologies, UV-Vis and various gas responses were studied. The XRD analysis showed formation of nanocrystalline TiO ₂ , while polyaniline exhibited amorphous nature. Morphological analysis using scanning electron microscopy of PANi-TiO ₂ nanocomposite film revealed uniform distribution of TiO ₂ nanoparticles in PANi matrix. The absorption peaks in FTIR and UV-Vis spectra of PANi-TiO ₂ composite film were found to shift to a higher wave number as compared to those observed in pure PANi. The observed shifts were attributed to the interaction between the TiO ₂ particle and PANi molecular chains. The gas sensing properties showed the sensor exhibit selectivity to ammonia (NH ₃ ) at room temperature.