Well‐Defined Crystalline TiO 2 Nanoparticles Generated and Immobilized on a Colloidal Nanoreactor

We synthesized well‐defined, crystalline TiO 2 nanoparticles at room temperature by using spherical polyelectrolyte brush particles as a template. The template particles consist of a polystyrene core from which long chains of poly(styrene sodium sulfonate) are grafted. Tetraethylorthotitanate is hydrolyzed in the presence of brush particles leading to the formation of well‐dispersed TiO 2 nanoparticles ( d  = 4∼12 nm). Wide‐angle X‐ray scattering demonstrates that anatase nanoparticles with high crystallinity have been generated at room temperature. The as‐prepared TiO 2 nanocomposites present high photocatalytic activity for the degradation of Rhodamine B under UV irradiation. Finally, mesoporous TiO 2 structures with defined pore size are formed after calcination.