Dmitry S. Shtarev

Photocatalytic Degradation of the Diesel Fuel by Using the Calcium Bismuthate - Bismuth Oxide Photocatalyst Composition

This paper provides new data on the visible light catalytic degradation of aqueous solution of diesel fuel on the calcium bismuthate - bismuth oxide catalyst compositions. It also investigated the toxicity of the catalyst composition and the products of the catalytic decomposition of diesel fuel.

Application of pyrolitic method of synthesis for preparation of calcium bismuthate based photocatalyst

The study describes use of pyrolytic synthesis method for preparation of visible light calcium bismuthate based photocatalyst. The advantage of the proposed method is that it allows obtaining single-phase, homogeneous samples with various types of crystal lattice and controlled defects. It is shown that it is possible to obtain crystalline calcium bismuthate with the same stoichiometry in the entire region of existence of the solid solution. Synthesized samples of calcium bismuthate have been characterized using the scanning electron microscopy and X-ray analysis. It was found that the scope and conditions of synthesis affect the degree of imperfection of both anionic and cationic sublattice of calcium bismuthate.

Photographic materials with direct blackening based on polymer-semiconductor compositions

Photographic properties of polyvinyl alcohol (PVA)-ZnO/TiO2 compositions sensitized by BiCl3 were investigated in a process with direct blackening. These properties in general are similar to those of earlier investigated compositions sensitized by lead acetate (PbAc). Direct blackening in system with BiCl3 is more resistant to moisture.

On the Question of the Choice of Reducing Agent Tungsten at Electroslag Remelting Flux Containing Scheelite Concentrate to Produce Tungsten Steel

Influence of various reducers of tungsten from a scheelite concentrate on a complex alloying of melted low-carbonaceous steel by tungsten through oxides slag system is investigated. By electroslag remelting of low-carbon steel with use of ceramic gumboils on the basis of mineral associations are received high-alloyed by tungsten (to 20 wt.%) became.

Optical homogeneity and photorefractive properties of stoichiometric and congruent lithium niobate crystals grown using charges of different origins

A stoichiometric lithium niobate crystal (LiNbO3 st) and congruent lithium niobate crystals grown from a charge prepared using cyclohexanone as an extractant (LiNbO3 cong(CHN)) and a charge prepared using cyclohexanone and carboxylic acid dimethylamides as extractants (LiNbO3 cong(CHN + A)) have been characterized by photoinduced light scattering and laser conoscopy. The results demonstrate that the LiNbO3 cong(CHN + A) crystals are rather homogeneous along their growth direction and possess good optical properties, similar to those of the LiNbO3 cong(CHN) crystal. At the same time, the LiNbO3 cong(CHN + A) crystal offers significantly better electro-optical properties (re = 29.3 pm/V).

Hydrothermal synthesis of anatase nanocrystals

The hydrothermal synthesis of TiO2 (anatase) nanocrystals has been produced. The conditions of reproducible synthesis of anatase nanocrystals by thermal treatment of water solution of titanium isopropoxide and triethanolamine at T= 80-100°C by 48 h have been found. Phase composition of final product has been verified by TEM and XRD analysis. As it has been obtained, the dimensions of TiO2 particles varied in the range 10-100 nm with mean value of 45 nm.

Structural Features and Optical Properties of Lithium Niobate Crystals

The behavior of the band gap, photorefractive and electroconductive properties depending on the composition, structural features and the defect state of LiNbO3 crystals, nominally pure and doped, obtained both in a single and in different growing technologies, are studied by a set of methods.

Effect of preparation conditions of calcium bismuthate based photocatalyst on its catalytic properties

In this study, a series of calcium bismuthate samples having a different composition and type of crystal lattice was obtained. The diffuse reflectance spectroscopy found that both factors impact the calcium bismuthate ability to absorb the visible light irradiation. It was shown that the bandgap of synthesized photocatalysts depends on the degree of lattice defects. The catalytic activity of photocatalysts was studied in terms of decomposition rate of methylene blue by visible light in the presence of various samples of calcium bismuthate. It was found that the catalytic activity of calcium bismuthates with orthorhombic crystal lattice is lower than that of similar samples of rhombohedral lattice. Thus, samples with the lowest number of cation sublattice defects have the greatest catalytic activity.