Non-template synthesis of titania hollow spheres and their thermal stability

Uniform and thermally stable spherical titania particles with hollow interiors were directly prepared by a novel solvothermal precipitation of TiCl4 in isopropanol without templates or shape-controller reagents. An average particle size of 700 nm to 1 mu m was obtained. The hollow spheres consisted of pure anatase phase nanocrystals with an estimated crystallite size of 12-15 nm. Upon heating, the pure anatase phase was retained for temperatures up to 800 degrees C, which suggested that the spherical structure contributed to phase stability. This method is a promising process for industrial -scale preparation of titania hollow spheres.