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The current research deals with the urgent task of creating highly efficient photocatalysts for wastewater treatment from various organic pollutants. For these purposes, we carried out a mechanochemical synthesis, heat treatment, and study of a non-toxic, thermally and chemically stable catalysts with a heterostructure based on Fe 2 TiO 5 pseudobrookite. The morphology and the properties of the as-prepared composites were characterized through different techniques. The chemical reactions occurring during the step-by-step heat treatment of the samples were proposed using info from XRD analysis, IR spectroscopy, thermal analysis, and mass spectra. The influence of the gaseous medium on the phase composition and the degree of crystallinity of materials has been established. The analysis of the elemental composition and morphology of powder particles was carried out at an annealing temperature in the range from 100 to 1000 °C in air. The photocatalytic activity of pseudobrookite was studied during the decomposition of the organic dye Rhodamine B, and the mechanism of photocatalysis associated with the absorption of photons and the formation of an electron-hole pair was considered. It was found that samples thermally treated in nitrogen were demonstrated greater catalytic activity than those treated in air. • Precursor of Fe 2 TiO 5 pseudobrookite was obtained by solid-phase synthesis. • Heating the obtaining powder resulted to the formation of the Fe 2 TiO 5 crystalline phase. • Powders exhibited photocatalytic activity upon discoloration of the Rhodamine B solution. • For the powder calcined in nitrogen, the photocatalytic activity was higher than that for air. [ABSTRACT FROM AUTHOR]

Abstract: Transport processes taking place during a metal anodic dissolution that accompanied by formation of the charged intermediate species are examined theoretically. Profiles of the component concentrations over the diffusion layer by quasi-equilibrium decomposition of intermediate species are calculated. It is shown that during the electrochemical process the anion’s concentration either increases or decreases as compared with its bulk value. What was the outcome depends on the stability constant of the complex species. For the first situation (increase in the anion’s concentration), analysis predicts the anion’s concentration limit depending on the stability constant of the intermediate particles. For the second case (decrease in the anion’s concentration), it is possible there is the limiting current value because of electroactive anion depletion in the near-electrode layer. [Copyright &y& Elsevier]

• Polystyrene/montmorillonite composite films were prepared via solution cast technique. • Plasma treatment of the produced films was carried out in low-pressure air plasma. • The water contact angle on the composite surface decreased after plasma treatment. • Plasma treatment of the composite led to an increase in MB adsorption efficiency. Polystyrene/montmorillonite (PS/MMT) composite films with high adsorption activity were prepared via solution intercalation technique followed by treatment of composite films in low-pressure air plasma. Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and scanning electron microscopy were used to investigate the impact of plasma on the elemental composition and morphology of the composite surface. It was revealed that plasma treatment of the PS/MMT composite led to an increase in wettability and adsorption performance. The removal kinetics of methylene blue dye from aqueous solutions was experimentally studied. It was determined that plasma processing of the composite resulted in a significant improvement of the MB adsorption process: the initial rate of the process increased by 4 times (from 1.2 × 10−8 to 4.8 × 10−8 mol/(g•min)). Adsorption kinetic curves are obeyed the pseudo-second order reaction equation. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: The experimental data on the nickel anodic dissolution in water-organic sodium chloride solutions are presented. The analysis of obtaining results is carried out by the fractal geometry approaches. The fractal dimension values as quantitative characteristics of the metal surface energy heterogeneity are determined. It is shown that the fractal dimension depends on the solution composition. [Copyright &y& Elsevier]

• Two-component ionogels containing clay minerals and ionic liquids were prepared. • The thermal behavior of the synthesized ionogels and pristine ILs was investigated using DSC and TG techniques. • A confinement effect was revealed in the studied materials. • The glass-transition temperature shifted towards higher temperatures with the introduction of aluminosilicate. • The characteristic temperatures of thermal decomposition of ionogels were lower than those for the pristine ILs. Two-component ionogels containing clay minerals such as montmorillonite K 10 (Mnt- K 10), bentonite (Bent), and halloysite (Hly), as well as imidazolium-based ionic liquids (ILs) were prepared in present work. The ILs that were used in the synthesis included a bis(trifluoromethylsulfonyl) imide anion (TFSI-) and various cations: 1-ethyl-3-methylimidazolium (EMIm+), 1-propyl-3-methylimidazolium (PMIm+), 1-butyl-3-methylimidazolium (BMIm+), and 1-butyl-2,3-dimethylimidazolium (BDMIm+). The thermal behavior of the synthesized ionogels and neat ILs was investigated using differential scanning spectroscopy (DSC) and thermogravimetric analysis (TG). It was found that the thermograms of PMImTFSI, BMImTFSI, and BDMImTFSI showed inflections corresponding to glass-transition, which shifted towards higher temperatures with the introduction of aluminosilicate. The largest shifts compared to the neat ILs were observed for IL/Bent ionogels. It was assumed that the identified differences in the thermal behavior between the neat and clay-entrapped ILs (confinement effect) are associated with an increased role of ion-wall interactions compared to ion-ion interactions. When studying the thermal stability of the materials under consideration, two opposite trends were noted. On the one hand, the characteristic temperatures of thermal decomposition of the synthesized ionogels were lower than those for the neat ILs. But on the other hand, when introducing aluminosilicate into any IL, a decrease in the maximum rate of thermal decomposition was observed in accordance with series of IL > IL/Mnt- K 10 > IL/Hly > IL/Bent. [ABSTRACT FROM AUTHOR]