Raman and UV-Vis Absorption Studies on Nanosized TiO_2Particles

The nanosized TiO 2particles with different structures were prepared by Sol Gel method at pH1 and pH3. Raman measurement showed that the samples obtained after heating them up to 674 K were mixtures of brookite and anatase. The Raman peak located at 157 cm -1 of sample A1, a mixture of brookite and anatase, was divided into two features by fitting technique, which are related to the spectra of them separately. UV Vis spectra show that the UV absorption of the superfine anatase particles are better than that of brookite and rutile. While commercial anatase (sized ～20 μm) has even lower UV absorption than that of nanosized brookite and rutile obtained by this work, suggesting that the quantum sized effect and the surface defects are also important factors to UV absorption of TiO 2particles.