Growth and characterization of optically confined particulate films of anatase TiO2

TiO2 particulate films with optically confined anatase phase were deposited on glass substrates using an aqueous precursor by dip-coating method. The precursor solution was prepared by mixing appropriate amounts of titanium tetraisopropoxide, isopropyl alcohol, and Triton X-100 in an airtight vessel. Without further treatment, the solution was used for the coating process. After deposition, the films were baked at 300 degrees C, 450 degrees C, and 600 degrees C for 15 min in air atmosphere using a box furnace. Physical properties of such films were investigated by X-ray diffraction, scanning electron microscopy, and UV-visible spectrophotometry. Effective mass approximation theory was applied to explain the optical confinement effect which is realized in those films because of its crystallite size. The energy bandgap values for the confined anatase phase of TiO2 particulates were predicted by the effective mass approximation model and are in good agreement with our experimental results. These observed results were discussed in detail.