9
Spectroscopic Investigation on Sol Gel Derived TiO2 Nanoparticles
Authors: Praveen Kumar Singh, Soumya Mukherjee, Chandan Kumar Ghosh, Saikat Maitra
Number of views: 486
TiO2 nanoparticles were synthesized by sol-gel method from titanium tetra isopropoxide. Influence of heat treatment on structural and morphological properties of TiO2 nanoparticles was investigated by XRD and SEM. Spectral properties of the nanoparticles were investigated using FTIR, Raman spectroscopy, PL spectroscopy and UV–visible absorption spectroscopy. XRD analysis revealed the formation of mixed anatase and ruitle phase in the synthesized powder at 550oC and existence of only rutile phase at 750 and 900oC. The lattice parameters, crystallite sizes, volume of the unit cell, density and surface area of TiO2 nanoparticles were determined from XRD analysis. SEM analysis showed that the prepared nanoparticles were in the nano regime, nearly spherical and larger agglomerated at lower temperature. EDX analysis showed that the TiO2 composition obtained was near stoichiometric at lower temperature and the proportion of oxygen vacancy increased with the increase in temperature. The presence of Ti-O and Ti-O-Ti bonds was confirmed by FTIR spectra. PL spectroscopy showed that the change in surface states and presence of anatase and rutile phases of TiO2 were also responsible for exhibiting the change in PL intensity. UV–visible absorption spectra showed the shifting of absorption edge towards the higher wavelength with the increase in temperature while the corresponding energy band gap of semiconductor nanoparticles decreased. Change in Raman spectra with the increase in temperature was observed due to anatase to rutile phase transformation and with the increase in the particle size.