S. A. Kuznetsova

Microwave synthesis of a photocatalytically active SnO-based material

Tin(II) oxide nanopowder has been prepared through microwave processing of an ammoniacal Sn6O4(OH)4 suspension, and the effect of synthesis duration on the surface morphology, acid-base properties, and photocatalytic activity of the SnO has been examined. The results demonstrate that the surface morphology plays a key role in determining the photocatalytic activity of powder SnO for methyl orange photo-degradation.

Film-Forming Capacity of Sn(II), Zr(IV), and Hf(IV) Acetylacetonates

Zr(acac)4, Hf(acac)4, and SnHacacCl2 · 2H2O were prepared in the solid state and in enthanol solutions. The film-forming capacity and thermal stability of these compounds were studied. Films of ZrO2, HfO2, and SnO2 were prepared from film-forming solutions of the corresponding acetylacetonates.

Composition and properties of CeO2-SiO2 composite films prepared from film-forming solution

This study focuses on the preparation and properties of CeO2-SiO2 thin films with thickness ≤60 nm that can be used as protective coatings for solar cell panels and electrochromic counter electrodes. Thin-film CeO2-SiO2 systems on glass and quartz substrates, which are manufactured from film-forming solutions based on cerium(III) nitrate, salicylic acid, and tetraethoxysilane and thermally treated, are mixtures of cerium(IV) (cubic modification) and silicon(IV) (amorphous phase) oxides. The films synthesized are distinguished by a net structure and high visible transmittance (∼90-100%). The morphology, phase composition, and optical properties of films were studied by X-ray diffraction, X-ray spectral microanalysis, scanning electron microscopy, spectrophotometry, and ellipsometry.

Synthesis of Transparent Conductive Coating In2O3:Sn Films from Film Forming Solutions

Materials based on films In2O3:Sn found commercial use as optical materials because of their high reflectance in infra red radiation and transmittance in visible spectrum. This paper investigates effects of treatment of glass substrates with acid (СН3COOH), basic (NaOH) etchants and an etchant having oxidation ability and acidic properties (chromic mixture) on optical properties of films In2O3:Sn proposed for solar cells and LEDs. The resulting films are characterized by high transparency 75-90% in visible spectrum for the values of refractive index 1.82-1.90. Substrate treating effect on thickness, resistance and transparency of the films is described. Morphology and optical properties of the films were studied by three-dimensional non-contact profilometry, spectrophotometry and ellipsometry.

Synthesis of CeO2/SnO2 catalytically active materials using film-forming solution

A procedure is proposed for the synthesis of CeO2/SnO2 catalytically active materials using an ethanolic film-forming solution containing cerium(III) nitrate and salicylic acid. We have studied the surface morphology of materials prepared by this procedure and assessed their catalytic activity for deep oxidation of hydrocarbon fuels.

Synthesis of supported SnO2–CeO2 catalysts for the deep oxidation of methane

A new method has been proposed for the synthesis of catalytically active 80 wt % SnO2 + 20 wt % CeO2 materials supported on glass fiber, which involves the use of an ethanolic film-forming solution based on cerium(III) nitrate and salicylic acid, with the addition of tin(IV) chloride. We have studied the morphology of the materials thus prepared and assessed their catalytic activity for the deep oxidation of methane. The results indicate that the appreciable catalytic activity of the materials is ensured by their uniform distribution over the support surface and the small oxide aggregate size ( 10 μm), which is due to the use of the filmforming solution of the proposed composition.

Synthesis and properties of SnO prepared from ammoniacal and carbonate suspensions of tin(II) hydroxy compound under microwave radiation

SnO powder was prepared by microwave treatment of ammoniacal and carbonate Sn6O4(OH)4 suspensions. It was shown that the type of the precipitant (aqueous ammonia and sodium carbonate) for Sn(II) hydroxy compound affects the surface properties of the resulting oxide. It is found that SnO powders prepared by homogeneous precipitation of tin(II) hydroxy compound with sodium carbonate, followed by the microwave treatment, have the smaller specific surface area (~0.4 m2 g–1) and contain agglomerates of the larger size (~50 µm) joint together into a “flower.”

Film-forming capacity of alcoholic solutions of iron(III) chloride with acetylacetone

Processes in which film-forming solutions based on acetylacetonate and iron(III) chloride are produced were subjected to a physicochemical study. Spectrophotometry and IR and UV spectroscopies were used to analyze the composition of the complex in propanol-2 and ethanol.

Sol–gel synthesis of Ta 2 O 5 –SiO 2 composites from tantalum(V) chloride and tetraethyl orthosilicate in ethanol

Ta2O5–SiO2 composites containing 10, 50, and 90 wt % SiO2 have been prepared by a sol–gel process in ethanolic solutions of tantalum(V) chloride with tetraethyl orthosilicate. The physicochemical aspects of their formation have been studied by IR spectroscopy, X-ray diffraction, X-ray microanalysis, and thermal analysis in combination with mass spectrometry. The results demonstrate that the SiO2 content of the Ta2O5–SiO2 composites influences the uniformity of the tantalum and oxygen distributions on the surface of the materials and that heat-treatment conditions influence their crystallinity.

The processes in film-forming solution based on tetraethoxysilane, phosphoric acid and calcium chloride

Physical and chemical patterns film-forming ethanol solution based on tetraethoxysilane, orthophosphoric acid and calcium chloride have been determined. Methods of photon correlation spectrometry and electrophoresis showed that colloidal particles with size up to 25u2005nm are formed in the film-forming solutions. Their stability is maintained during one day, and then CaHPO4 precipitates from the film-forming solutions. Methods of X-ray analysis, scanning electron microscopy and IR spectroscopy have shown that the dried coating solution after precipitation of CaHPO4 consists of CaClH2PO4·H2O and SiO2. The formation of these substances is due to the hydrolysis of tetraethoxysilane and interaction calcium chloride with orthophosphoric acid.