Enhanced Photocatalytic Activity of TiO₂/SnO₂ Binary Nanocomposites

Abstract

The paper presents the results of characterization and study of adsorption-photocatalytic properties of commercial and synthesized-by-hydrothermal method TiO 2 and TiO 2 -SnO 2 nanocomposites. Hydrothermal synthesis of TiO 2 -based nanocomposites was performed in two ways: single-stage and two-stage methods. Characterization was carried out by XRD, X-ray fluorescence method, XPS, EPR, PL, and low-temperature adsorption-desorption of nitrogen, which showed that TiO 2 -SnO 2 nanostructured composites were obtained with tin(IV) oxide content of 10 wt.% and had acidic surface and different porous structures. Besides, modification of a commercial sample with tin(IV) oxide led to a slight decrease in the specific surface area, while modification of a synthesized-by-hydrothermal method TiO 2 sample led to an increase. It was found that sorption properties of the obtained nanocomposites and pure TiO 2 are better towards anionic dyes. Photocatalytic activity, on the contrary, is higher towards cationic dyes, which is consistent with additional studies on the destruction of these dyes. It was established that in terms of photocatalytic activity, TiO 2 -SnO 2 nanocomposites are more promising than solid solutions, and modification of TiO 2 with tin(IV) oxide, in general, leads to improvement of its photocatalytic activity.