On the nature of the phase "η-TiO2"

• Main Authors: Vasilyeva, Inga, Kuz'micheva, Galina, Pochtar, Alena, Gainanova, Asiya, Timaeva, Olesya, Dorokhov, Andrey, Podbel'skiy, Vadim
• Format: Journal Article
• Language: English
• Published: 01.01.2016
• ISSN: 1144-0546; 1369-9261
• DOI: 10.1039/c5nj01870f

Conditions for a sulfate method for the synthesis of a metastable modification, which has been previously described as "η-TiO 2 " (Dadachov, 2006), were found and the stability region of this phase in the hydrolysis temperature-hydrolysis duration coordinates was determined. Investigation by a number of methods (X-ray powder diffraction, a differential dissolution method, thermogravimetry, IR spectroscopy, Raman spectroscopy) showed that the η-phase is not a polymorph of TiO 2 but is a pseudo-polymorph of titanium dioxide hydrate. It was demonstrated that nanoparticles of the low-temperature η-phase consist of the [TiO 2− x · m H 2 O] core, the structure of which can be described as a superstructure in relation to anatase, and an amorphous shell containing TiO 2− x (trace amount), OH, HSO 4 and water. The average crystallite size depends on the ratio of the constituents. The low-temperature η-phase consists of a [TiO 2− x · m H 2 O] core and an amorphous shell containing TiO 2− x (trace), OH, HSO 4 and water.