Synthesis of TiO2nanoparticles via a simple precipitation method and photocatalytic performance

Titanium dioxide nanoparticles were prepared by a simple precipitation method using titanium (IV) isopropoxide as a starting material. The precursor powder was calcined in air at temperatures ranging from 400 to 700 °C. XRD analysis results revealed that the crystallite size and crystallinity of the samples increased with increasing calcination temperature. The morphology and particle size of TiO2 particles were investigated with TEM images and the diameter of the particles was then calculated using the images. It was evident that the calcination temperature had a significant influence on the average particle size since the size increased from 11.3 to 27.4 nm when the temperature was raised from 400 to 700 °C. By extrapolating the graph of (αhv)n versus photon energy (hv) to the horizontal axis, the energy band gap (Eg) of the calcined TiO2 nanoparticles was in the range of 2.98–3.30 eV. Under UVA irradiation, photodegradation activity of methyl orange had the fastest kinetics as measured by areaction rate constant, k, using the pure anatase TiO2 nanoparticle calcined at 400 °C.