An effective method for controlling the nanoparticle size of anatase TiO2

Uniform anatase-type titania (TiO₂) nanoparticles were prepared by controlling gelation pH during the sol-gel process. Particle size of the anatase TiO₂ was increased from ca. 7 to 23 nm with the pH increasing from 2 to 9. When pH value was 10, particle morphology showed spheroids and square shapes because of the formation of an anatase phase and hydrogen titanium oxide. Optimal preparation condition was at pH 2, with fine nanoparticles forming the anatase phase at ca. 10 nm. Results indicated that it was an effective method to control the crystallite size of anatase-type TiO₂ by adjusting the pH values of sol during the sol-gel process.