Spectroscopic analyses of the photocatalytic behavior of nano titanium dioxide

Nano titanium dioxide TiO₂ was synthesized using hydrolysis method then subjected to several characterizations. XRD revealed that the as-prepared sample is pure anatase phase and after calcinations at 500 °C for 3 h the crystallinity has increased. The crystallite size calculated by Debye-Scherrer's formula is 8 nm. The HRTEM image shows an average size of about 9 nm, which is close to the XRD calculation from Scherrer's formula. PM3 semiempirical quantum mechanical calculations were conducted to present the electronic as well as thermal properties for TiO₂. FTIR spectra between 800 and 400 cm^-1 are the verification for the lattice vibrations of anatase TiO₂. The photo catalytic degradation of methylene blue (MB) was tested by the prepared nano TiO₂. Results indicate that, the maximum degradation efficiency reached 94.4% after 120 min of UV irradiation. This increase in the degradation efficiency of TiO₂ could be attributed to the reduction in particle size that enhanced the crystallinity as a result of heat treatment.