Direct Formation of Zirconia‐Doped Titania with Stable Anatase‐Type Structure by Thermal Hydrolysis

Nanoparticles of anatase‐type titania (TiO 2 ) doped with zirconia (ZrO 2 ) were directly synthesized from acidic precursor solutions of TiOSO 4 and Zr(SO 4 ) 2 by simultaneous hydrolysis, under mild hydrothermal conditions, at 200° and 240°C. Doping ZrO 2 into TiO 2 suppressed the crystal growth of anatase and shifted the phase transformation from anatase‐type to rutile‐type structure to a high temperature. The presence of an anatase‐type structure with high crystallinity and high phase stability, even after annealing at 1000°C for 1 h, was fully achieved by both the doping of ZrO 2 into TiO 2 through direct precipitation and the simultaneous hydrolysis of the sulfate solutions.