Effect of the Amount of H2O on the Crystallization of TiO2 Films Prepared from Alkoxide Solutions Containing Acetylacetone



Sol–gel-derived TiO2 films were prepared by dip-coating from Ti(OC3H7i)4–CH3COCH2COCH3–HNO3H2OC2H5OH solutions, and the effect of the H2O content in solutions on the crystallization of TiO2 films during the heat treatment at 800°C was discussed. The crystalline phase, crystallite size, grain size, and refractive index of the TiO2 films depended on the H2O/Ti(OC3H7i)4 mole ratios (x) in the coating solutions. Highly dense and crystalline rutile films were obtained at = 0.5–10, where the crystallites and grains became larger with increasing x. The further increase in x from 10 to 50 reduced the crystallite size and refractive index of the films, where anatase phase appeared at = 30–50.