Estimation of band gap and particle size of TiO2 nanoparticle synthesized using sol gel technique

In this study, a sol-gel method was used to obtain titanium dioxide nanoparticles. Titanium isopropoxide was used as a precursor and Hydrochloric acid was added to adjust the pH of the solution. The sol obtained was dried at 80°C and calcined at 450°C for 3hrs. The UV absorption spectra of synthesized TiO2 sample exhibited strong absorptions below 400 nm. The band gap is estimated using the (αEphot)^2 versus Ephot plots. The band gap was found to be 3.4 eV for the synthesized sample which was larger than 3.2 eV for bulk TiO2. Also XRD analysis was carried out for the sample and the crystal size was calculated by Scherrer's formula. The Scanning Electron Microscope images confirmed the nano size of synthesized particle.