Synthesis, characterization, material properties and sensor application study of polyaniline/niobium doped titanium dioxide nanocomposites

Conducting polyaniline (PANI)/niobium doped titanium dioxide (Nb–TiO₂) nanocomposites with different weight percentages of Nb–TiO₂ nanoparticles were synthesized by an in situ polymerization method. The synthesized materials were characterized by FT-IR, UV, XRD, SEM, HRTEM, TGA, DSC and electrical conductivity measurements. Also, the ammonia gas sensing properties of PANI and its nanocomposites have been explored thoroughly. The FT-IR and UV spectra showed the clear evidences for the presence of nanoparticles by shifting to a broad peak, which indicates the interaction of nanoparticles with PANI. The XRD study reveals the crystalline nature of the fabricated nanocomposite. SEM and TEM analysis indicates the uniform dispersion of nanoparticles in the polymer matrix with spherically shaped particles having the nano-size region. TGA analysis showed the increased thermal stability of nanocomposites with an increase in concentration of nanoparticles. The increase in glass transition and melting temperature with the increase in content of nanoparticles were obtained from DSC. Both AC and DC conductivity and dielectric properties of the nanocomposites were increased with the increase in content of nanoparticles and the maximum electrical properties were obtained for 10 wt% of composite. The fabricated composites showed excellent sensitivity and fast response to ammonia gas at room temperature. The effect of nanoparticles in the polymer chain increases the potential application of the conducting polyaniline, can act as multifunctional promising new material such as nanoelectronic devices and sensors.