Photoluminescence Probing of the Formation of Titanium Dioxide Sols from a Titanium Peroxide Solution

Photoluminescence spectroscopy was used to probe the formation of colloidal TiO2 sols from a titanium peroxide solution, which were prepared by reaction of H2O2 and titanium hydrate gel that was precipitated from acidic TiOCl2 solution neutralized by NH4OH, during aging at 100°C for 0–64 h. Emission spectra revealed broad band luminescence which is interpreted as the superposition of a multiple photoluminescence process involving TiO2 precursors. The maximum peak position of the luminescence band was shifted to a shorter wavelength by the generation of the dominant emission peak as aging time increased, and a peak at ∼390 nm, indicating the anatase phase, was observed after aging for >48 h. However, sols aged for 2 h already were of the anatase phase, according to X‐ray diffraction analysis. It was deduced that the interfacial layers between the particles and the liquid in an aqueous solution caused luminescence quenching or accelerated sink.