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.