Structural characterization of TiO2 ultrafine particles

Four samples of TiO2 ultrafine particles (UFP) were obtained through different processes. The structure of TiO2 ultrafine particles and the factors influencing the structure were investigated with Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and x-ray diffraction (XRD). Both Raman spectra and x-ray diffractograms show the similar regularity of the phase transformation among the four samples. The observed bimodal lineshape-structure in the Raman spectra is attributed to the intragrain and grain-boundary components of TiO2 UFP. The crystal structure of TiO2 UFP is found to be distorted by the surface structure such as OH and OCH2CH3 groups coordinated on the surface of TiO2 UFP.