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

Abstract

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 (E_g) 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