Strengthening of Spherical V2O5/TiO2−SiO2 Composites Obtained by Template Synthesis Combined with Sol-Gel Method

Abstract

This study is devoted to the preparation of strong spherical V₂O₅/TiO₂–SiO₂ composite by a combined template and sol-gel method. The composition, size, and shape of the colloidal particles in butanol sol with tetrabutoxytitanium and tetraethoxysilane have been determined. The physicochemical processes leading to the strengthening of the spherical agglomerates obtained using an anion exchanger with a gel structure have been established. Electrophoresis, small-angle X-ray scattering, and viscometry have been used to demonstrate the presence of positively charged colloidal particles of lenticular and cylindrical shape in the sol. The size of the particles, when the sol is stabilized, reaches 53 Å. The absorption of the sol by the anion exchanger in vanadium form is due to the equalization of the osmotic pressure in the anion exchanger/sol system. Spherical composites with a diameter of 300 µm have been obtained. It has been shown by X-ray powder diffraction that the composites consist of V₂O₅ with an orthorhombic structure, TiO₂ with an anatase structure, and amorphous silicon dioxide. The interaction at the interface between the phases of V₂O₅ with TiO₂ and SiO₂ has been demonstrated by IR and Raman spectroscopy. This interaction leads to the strengthening of the sphere of the V₂O₅/TiO₂–SiO₂ composite. The results obtained can be used for the synthesis of the spherical M_xO_y/TiO₂–SiO₂ composites.