Reactivity of Aluminum and Titanium Oxides under the Conditions of the Synthesis of Strontium and Barium Titanates in Water Fluid Media

• Published in: Russian journal of physical chemistry. B 2020-12, Vol.14 (8), p.1252-1259
• Main Authors: Lagunova, E. A., Ivakin, Yu. D., Sinev, M. Yu, Shashkin, D. P., Gordienko, Yu. A., Fattakhova, Z. T.
• Format: Article
• Language: English
• Subjects: Aluminum hydroxide; Aluminum oxide; Barium; Barium titanates; Basic oxides; Boehmite; Chemistry; Chemistry and Materials Science; Physical Chemistry; Precursors; Scanning electron microscopy; Spatial distribution; Spectrum analysis; Strontium; Strontium oxides; Strontium titanates; Titanium; Titanium oxides; X ray powder diffraction; X-ray diffraction
• ISSN: 1990-7931; 1990-7923
• DOI: 10.1134/S1990793120080047

Strontium and barium titanates deposited on a porous support (α-Al 2 O 3 ) are synthesized by the treatment of previously deposited precursors (titanium oxide, strontium nitrate, or barium nitrite) in a water fluid medium at 400°C. The obtained samples are characterized by X-ray powder diffraction (XRD) analysis and scanning electron microscopy (SEM) with energy-dispersive X-ray (EDX) spectroscopy. It is found that, in the presence of titanium oxide, α-Al 2 O 3 is partially hydrated to form basic aluminum hydroxide AlO(OH) (boehmite), which is not detected by XRD after the treatment of α-Al 2 O 3 in a water fluid. SEM with EDX spectroscopy demonstrates that strontium ions under the conditions of the treatment in a water fluid preferably interact with titanium oxide to form SrTiO 3 , although the aluminum oxide content in the samples is much higher. The conditions are determined for obtaining systems with different spatial distributions of the supported component inside the granules of the support by varying the procedure of its preliminary impregnation with the titanium oxide precursor.