Silica-Supported Titania-Zirconia Nanocomposites: Structural and Morphological Characteristics in Different Media.

A series of TiO2-ZrO2/SiO2 nanocomposites were synthesized using a liquid-phase method and characterized by various techniques, namely, nitrogen adsorption-desorption, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, high-resolution transmission electron microscopy, and photon correlation spectroscopy (PCS). It was revealed that the component ratio and calcination temperature affect the phase composition of nanocomposites. Composites TiZrSi1 (TiO2:ZrO2:SiO2 = 3:10:87) and TiZrSi2 (10:10:80) calcined at 1100 °С demonstrate the presence of t-ZrO2 crystallites in TiZrSi1 and ZrTiO4 phase in TiZrSi2. The samples calcined at 550 °С were amorphous as it was found from XRD data. According to the Raman spectra, the bands specific for anatase are observed in TiZrSi2. According to XPS data, Zr and Ti are in the highest oxidation state (+4). Textural analysis shows that initial silica is mainly meso/macroporous, but composites are mainly macroporous. The particle size distributions in aqueous media showed a tendency of increasing particle size with increasing TiO2 content in the composites.