Figure 2 shows UV-Vis spectrum for TiO2 nanoparticles. UV-Vis parameters such as
absorption, indirect band gap, refractive index, real dielectric constant, imaginary
dielectric constant, extinction coefficient, and optical conductivity of as synthesised TiO2
nanoparticles were study using UV-Vis spectroscopy. UV-Vis spectroscopic analysis was
carried out through Agilent Technologies, Cary 60 UV-Vis. From Figure 2, observed that, % absorption is higher on the lower wavelength side. Material exhibits absorption
around the 210–300 nm. In TiO2, the valence band is composed of O 2p states while the
conduction band is composed of Ti 3d states (Nagao et al., 2010). The absorption peaks
around 220 nm and 320 nm is due to electronic transition from O 2p to Ti 3d and
maximum absorption occur when electrons are excited from the valence to the
conduction band.