Facile synthesis of blue anatase TiO2 films by solvent evaporation method

With arousing interest in the preparation of defect rich TiO 2 films for several green energy applications, various methods have emerged in recent days. Herein, we report the properties of blue anatase TiO 2 films obtained by combined solvent evaporation and subsequent calcination. The X-ray diffraction and Raman studies indicated the formation of anatase TiO 2 films, while the field emission scanning electron microscopic images confirmed the distribution of spherical particles. X-ray photoelectron spectroscopic data revealed the presence of surplus Ti 3+ ions and the associated oxygen vacancies. These defect related informations are further evident from the photoluminescence study. The optical study confirmed the extended absorption in the visible region of the blue TiO 2 films. These intrinsic defects play a major role in effective charge carrier separation and in tailoring the band gap absorption properties.