Russian Journal of General Chemistry最新文献

Herein, the previously reported Co-(3-AIN)-bio-MOF, which possesses a rigid one-dimensional channel structure, was selected as sulfur host to construct a cathode for lithium-sulfur batteries. The as-synthesized MOFs and the resulting MOF@S composite were thoroughly characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), inductively coupled plasma mass spectrometry (ICP-MS), and Fourier-transform infrared spectroscopy (FTIR). Electrochemical performance evaluations demonstrated an initial discharge specific capacity of 851.61 mAh g^–1 at 0.1 C, with a retained capacity of 555.63 mAh g^–1 even at higher current rates. When the current rate was switched back to 0.1 C, a reversible capacity of 894.04 mAh g^–1 was achieved, which corresponds to a 100 % recovery of the initial capacity. The results indicate that the cobalt-based MOF endows the sulfur cathode with high specific capacity, excellent cycling stability, and outstanding reversibility, demonstrating its promise for use as a cathode material for Li-S batteries. This work presents a novel strategy to tackle the critical challenges of poor solid-liquid interface contact and the polysulfide shuttle effects in sulfur-based cathodes.

Reactions of N-vinylpyrrolidone (1-ethenylpyrrolidine-2-one) with arenes under the action of the Brønsted superacid CF₃SO₃H (triflic acid, TfOH) or strong Lewis acids AlX₃ (X = Cl, Br) at room temperature for 1.5 h afford N-(1-arylethyl)pyrrolidones as products of hydroarylation of the N-vinyl group in 11–85% yields. The key intermediate of this transformation is O,C-diprotonated form of N-vinylpyrrolidone, which is a highly reactive electrophile, according to DFT calculations. In the absence of arenes in TfOH, N-vinylpyrrolidone underwent devinylation to form NH-pyrrolidone.

Based on the results of a comprehensive study of the physicochemical properties of carbonaceous materials of technogenic and natural origin, including the determination of their elemental, technical, phase composition, structural characteristics of the surface, thermal stability in an inert environment, the choice of coke fines and anthracite as reducing agents in the process of metallization of finely dispersed waste of metallurgical production with an iron content not exceeding 35% calculated as Fe₂O₃, represented mainly by franklinite and zinc oxide phases, is substantiated. The consumption of carbonaceous materials, which achieves a metallization degree of at least 97%, complete extraction of zinc and the regulated content of sulfur, phosphorus and gangue (SiO₂) in the reduction products, was experimentally determined. It was established that the main criterion for the efficiency of carbonaceous materials in the processes of reduction of waste of metallurgical production with an iron content not exceeding 35% in terms of Fe₂O₃ is the chemical and phase composition of inorganic impurities.

The process of phenol biodegradation using a biocomposite obtained by immobilizing Debaryomyces hansenii D-43-1 yeast on a bacterial cellulose gel film was studied. It was found that in the presence of the biocomposite, due to the high water content in the cellulose gel film, the phenol concentration in the model effluents decreases to a level that allows the immobilized yeast to carry out its efficient biodegradation. Conditions were identified that enable the use of the developed biocomposite for the complete biodegradation of phenol in a highly concentrated model effluent containing 2200 mg/L of the toxicant within 7.5 h.

The authors of the article determined the corrosion rate of steel samples of several grades, and also investigated the dynamics of changes in the strength properties of rubber and plastic materials used for the manufacture of the casing and parts of downhole electric pump units. Experimental studies were carried out in model environments of different composition at different temperature and time regimes simulating the operating conditions of the units.

This study presents, for the first time, the results of modeling the interaction of mine waters from the Perevalnoe deposit (Komsomolsky District) with the main sulfide minerals of tin–lead–zinc ores. The research employed physicochemical modeling using the Selektor software package. Simulations were conducted across a wide temperature range (–25 to +45°C). Eh–pH parameters of the resulting solutions, their ionic and molecular composition, as well as the paragenesis of precipitated technogenic minerals were determined in 26 experimental variants. Chemical interactions were examined both for individual sulfide minerals (native copper, cuprite, tenorite, chalcocite, covellite, bornite, galena, sphalerite, chalcopyrite, arsenopyrite, pyrite, pyrrhotite) and for their associations, including cases where one component was removed from the model system. The results demonstrate that technogenic mineral formation occurs throughout the entire temperature range studied.

The article presents the results of many years of research aimed at identifying problems in the development of the forestry industry in the Far Eastern Federal District, including the Khabarovsk Territory, and justifying the need to create resource-based plantations to achieve the geopolitical goal of consolidating the population in this territory and ensuring a comfortable human environment. Theoretical and experimental studies have revealed the possibility of effective cultivation of plantation forests by various methods using bioactivators (accelerators of growth processes). The highest rooting rates of poplar cuttings were found in Marilandica, Sakrau-59, Pioneer, E.S.-38, Chinese and Populus trichocarpa (P. trichocarpa) varieties. The best results were achieved by means of the “Rostivin” bioactivator. The novelty of the technological proposal is confirmed by the Patent of the Russian Federation (2024).

The article presents the results of a study of the lakes of Pinezhsky Nature Reserve, which is part of specially protected natural areas (SPNA). The lakes Sychevo, Zheleznoye, Kumichyovo and Pershkovskoye were studied. The characteristics of the hydrological and hydrochemical parameters obtained from observations in March 2022 and 2024 are provided. Changes in the hydrogen index (pH), mineralization, and biogenic elements (nitrate, nitrite, ammonium nitrogen, phosphate phosphorus and silicon) are shown. The compliance of the obtained parameters with the regulatory requirements for the quality of lake waters is assessed. Studies have shown that the waters of Lake Sychevo and Lake Zheleznoye are classified as low- mineralization reservoirs, Lake Pershkovskoye as high-mineralization reservoirs, and Lake Kumichyovo as highly mineralized reservoirs. The pH values in Lakes Sychevo and Zheleznoye are classified as slightly alkaline to neutral waters. Lakes Pershkovskoye and Kumichovo have a slightly alkaline water reaction. The concentrations of phosphorus, nitrogen and silicon salts over the entire observation period did not exceed the maximum permissible values ​​for fishery reservoirs. The results obtained allow us to conclude that there is no noticeable anthropogenic impact on the reservoirs in question. The purpose of the work was to identify the hydrological and hydrochemical features of the lakes under study. The data obtained can be used as background data for assessing the negative impact in the case of anthropogenic load on the river basin.

Levels of PCBs were determined in Comephorus baicalensis (Pallas, 1776), a pelagic sculpin endemic to Lake Baikal. Concentrations of PCBs were measured using GC/MS. The maximum concentrations over the entire study period (2000–2023) were found for ƩPCB₍₃₁₎ (694–1669 ng/g lw). The decreasing trend of ƩPCB(31) concentrations was revealed using the Mann–Kendall test. With regard to the percentage composition of the PCBs, increasing trends were found for PCB 99, PCB 85, PCB 118 and negative trends for PCB 28, PCB 149, PCB 132, PCB 126, PCB 177, PCB 170. The results indicate that the southern basin of Lake Baikal continues to experience considerable pressure from the ongoing influx of PCBs.

The effect of synthetic detergents on leguminous crops Vigna radiata and Lens culinaris was studied in Petri dishes. After four days of incubation, measurements of the seedlings were taken. It was shown that the plants lagged in growth and development during incubation. At concentrations of 2.5 g/L and 5 g/L, L.culinaris died. At a concentration of 0.5 g/L, inhibition was almost lethal (97.6‒98.1%) in lentils. Mung showed a higher degree of tolerance to all concentrations (except for Persil Color Plus 5 g/L, 100% inhibition). Interaction with detergents may lead to a decrease in the yield of legumes.