Anatase and rutile TiO2 monodisperse microspheres by rapid thermal annealing: A method to avoid sintering at high temperatures

Abstract

Submicrometer-size spherical TiO2 particles with crystalline framework and high refractive index have a wide range of technological applications; however, the synthesis of monodisperse non-aggregated rutile TiO2 spheres remains a challenge. We report here an inexpensive and simple method to obtain rutile non-aggregate TiO2 monodisperse spheres with submicrometer diameter. The methodology involves the synthesis of the microspheres by a sol–gel method and the transformation of the amorphous microspheres in rutile microspheres by rapid thermal annealing.