Synthesis and characterization of TiO2-doped Polyaniline nanocomposites by chemical oxidation method

Polyaniline (PANI)/TiO₂ nanocomposite samples with various dopant percentages of TiO₂ were synthesized at room temperature using a chemical oxidative method. The samples were characterized by ultraviolet-visible spectrometer, Fourier transform infrared (FTIR) spectrometer, X-ray diffraction (XRD), scanning electron microscopy (SEM), EDAX and conductivity measurements. Incorporation of TiO₂ nanoparticles caused a slight red shift at 310 nm in the absorption spectra due to the interactions between the conjugated polymer chains and TiO₂ nanoparticles with π–π^? transition. FTIR confirmed the presence of TiO₂ in the molecular structure. In PANI/TiO₂ composites, two additional bands at 1623 cm^?1 and 1105 cm^?1 assigned to Ti–O and Ti–O^–C stretching modes were present. It can be concluded that Ti organic compounds are formed with an alignment structure of TiO₂ particles. XRD patterns revealed that, as the TiO₂ percentage was increased, the amorphous nature disappeared and the composites became more strongly oriented along the (1 1 0) direction, which showed the tetragonal structure of nanocrystalline TiO₂. SEM studies revealed the formation of uniform granular morphology with average grain size of 200 nm for (50%) PANI/TiO₂ nanocomposite samples.