Investigations on structural, optical, and impedance spectroscopy studies of titanium dioxide nanoparticles

This article explains a novel synthesis for producing titanium dioxide (TiO2) nanoparticles by a sol-gel technique using titanium tetraisopropoxide as a titanium source. The synthesized nanoparticles were analyzed using many measurements like X-ray diffraction (XRD), HRTEM, absorption UV spectroscopy, FTIR, and ac impedance spectroscopy. X-ray peaks were used to calculate the crystallite size and lattice strain by Williamson–Hall method. Crystallite size calculated from x-ray diffraction using the Scherrer equation gives an approximate size and cannot be used for measurements. TiO2 nanoparticles are found to possess a tetragonal structure with a crystalline size around 12 nm. Particle size was confirmed by HRTEM images. The optical studies response for the nanoparticles showed the possible visible absorption peaks for TiO2 nanoparticles are 323 nm. Bandgap energy (Eg) of the TiO2 nanoparticle calculated from UV visible absorption spectra is discussed, and the bandgap is 3.14 eV. FTIR spectra showed vibration bands of the Ti-O network. AC Conductivity properties of TiO2 nanoparticles are studied in the frequency range 1 to 8 MHz at varying temperatures. The conductivity of the TiO2 nanoparticle is found to be constant in the low angular frequency region. Dielectric parameters were analyzed at different temperatures and frequencies. KEY WORDS: Conductivity, Dielectric, Nanoparticles, Titanium dioxide, Structural studies Bull. Chem. Soc. Ethiop. 2021, 35(1), 151-160. DOI: https://dx.doi.org/10.4314/bcse.v35i1.13