Nanoscale titanium dioxide modifications with anatase and η-TiO2 structures have been obtained by the sulfate method. Bands characteristic of the η-TiO2phase are selected in the Raman and IR spectra...

Samples containing anatase and η-TiO₂ nanoparticles have been prepared from titanyl sulfate solutions and characterized by X-ray diffraction, transmission electron microscopy, and electron diffraction. Unit-cell parameters of η-TiO₂ have been proposed that do not rule out a relationship between the anatase and η-TiO₂ structures. The samples containing anatase and η-TiO₂ differ in crystallite size and specific surface area and consist of agglomerates of particles of various sizes covered with an amorphous layer. We have studied the effect of synthesis conditions on the ability to prepare a particular titania polymorph with various functional characteristics.

A new phase, where peroxo groups are incorporated into titania particles, along with anatase and hydrated η-TiO₂ with peroxo groups on the surface of titania nanoparticles were prepared.

Iodides and polyiodides of scandium complexes containing urea (Ur) and acetamide (AA) have been synthesized and characterized by elemental analysis, IR spectroscopy, and X-ray diffraction. The trigonal crystals of [Sc(L)₆]I₃ (L = Ur, AA) and monoclinic crystals of [Sc(Ur)₆][I₃]₃ are isomorphous to the earlier reported [M(Ur)₆]I₃ (M = Ti, V, Cr, Fe) and [Ln(Ur)₆][I₃]₃ (Ln = Yb, Lu), respectively. Therefore, scandium in its complexes with urea and iodine links rows of 3d transition elements and rare-earth elements; it continues the tendency of formation of polyiodides with different structures from isomorphous iodides, which was found for other metal(III) urea complexes. In the orthorhombic crystals of [Sc(AA)₆][I₅][I₃]I, the first example of the M(III) acetamide polyiodide, metal ions in complex cations are located at the centers of distorted octahedral arrangements of oxygen atoms of acetamide; iodide ions are not coordinated. The crystals of [Sc(AA)₆][I₅][I₃]I contain V-shaped pentaiodide, linear triiodide, and isolated iodide anions.

A new method of sensitizing titania by treatment of the reaction mixture with Methylene Blue, Methyl Red or hydrogen peroxide is developed; the sensitizer was introduced into the reaction mixture while synthesizing nanosize TiO₂ from titanyl sulfate. The samples prepared by this method are compared to the samples prepared by cold impregnation of Methylene Blue, Methyl Red or hydrogen peroxide on titania, pre-synthesized by sulfate method, or commercial Degussa P25 and Hombikat UV100. The samples were characterized by X-ray diffraction; their photocatalytic activity was studied in the model reaction of Methyl Orange decomposition in aqueous solution under UV and visible light. The highest photocatalytic activity under visible light was found for titania, sensitized with titanium peroxo complexes by the new method. It is also active for photodegradation of salicylic acid under visible light.

The Raman spe ctra of the polyio di de complexes of d elements with urea (Ur) an d a cetami de (AA), namely, [M(Ur)6][I3]3 (M = Cr, Fe), Co(Ur)6][I3]2 · 2Ur, [Mn(Ur)6][I8], [Ni(AA)6][I3]2, [M(AA)6][I1