ИСТИНА

Layered perovskite-type oxides A2Ln2Ti3O10, containing interlayer alkali cations are considered as promising photocatalysts. The increase of alkali ion size in these compounds leads to higher photocatalytic activity. Despite this, Rb-containing titanates still remain poorly investigated. The aim of this work was to obtain Rb2Ln2Ti3O10 oxides, to study phase transformations of these materials in aqueous solutions, the isolation of the respective phases and measurement of their photocatalytic activity. The parent compounds were prepared by solid-phase synthesis. A new synthetic way was developed for the previously undescribed Rb2Nd2Ti3O10 oxide. Hydrated forms of the parent compounds and a number of partially protonated and hydrated phases, which are formed in aqueous medium under different conditions (pH, temperature, exposition time), were obtained. These phases were identified and characterized by powder X-ray diffraction, thermogravimetric analysis and SEM. The rate of H2 evolution during irradiation of these compounds suspended in diluted water-alcohol solution is several times higher than that for the conventional photocatalyst TiO2.