Lithium-ion batteries require cathode materials with high capacity and cycling stability. Li3V2(PO4)(3) (LVP) offers a theoretical capacity of 197 mAh/g but suffers from poor electronic conductivity. In this study, a Li3V2(PO4)(3)/carbon (LVP/C) composite was synthesized via a citric acid-assisted sol-gel method. The effects of pyrolysis temperature (700-1000 degrees C) and citric acid-to-salt ratio (1:1, 0.5:1, 0.25:1) were systematically investigated. The optimal composite was obtained at 900 degrees C with a 1:1 ratio. This material exhibited a well-crystallized monoclinic structure (space group P2(1)/c) with unit cell volume of 890.61 & Aring;(3). The amorphous carbon coating provided a specific surface area of 33.03 m(2)/g. Electrochemically, the optimal LVP/C_1:1 composite delivered an initial specific capacity of 114 mAh/g at C/10 rate-twice that of samples with lower carbon content. It also demonstrated 100% capacity retention after 25 cycles with favorable coulombic efficiency (67%) and reduced charge-transfer resistance. These results show that pyrolysis at 900 degrees C with a 1:1 citric acid-to-salt ratio provides an optimal balance between crystallinity, carbon coating uniformity, and electrochemical performance for high-performance LVP/C composite cathodes.

We report on the design and performance of composite sorbents based on 4',4”(5”)-di-tert-butyldicyclohexano-18-crown-6 and novel fluorinated diluents for the selective separation and pre-concentration of 210Pb and 210Po. The sorbents were synthesized by impregnation of a solid support with solutions of the crown ether in three fluorinated diluents: 3-nitrobenzotrifluoride (F-3), bis(2,2,3,3-tetrafluoropropyl) carbonate (BK-1), and bis(2,2,3,3-tetrafluoropropoxy)-methane (FN-1). The synthesis was optimized with respect to the choice of support, solvent, and key conditions—namely, impregnation temperature and time, as well as crown ether concentration. Optimal performance was achieved using a styrene–divinylbenzene support (LPS-500, 50–60 μm) impregnated with 1 mol L–1 crown ether solution in the diluent, using chloroform as a solvent which was subsequently removed. The materials were comprehensively characterized by IR spectroscopy, XPS, SEM, and EDS. These analyses confirmed the successful incorporation of active components into the support. Among the studied diluents, BK-1 provided the highest lead distribution coefficients, reaching up to (8.6 ± 0.6)·103 mL g–1. Efficient recovery of 210Pb and 210Po from 1 mol L–1 HNO3 was achieved with distribution coefficients values up to 7.05·103 and 2.93·103 mL g–1, respectively, and quantitative desorption was accomplished using 5–6 mol L–1 HCl. This combination of high distribution coefficients, pronounced selectivity in acidic media, and facile regeneration using HCl solutions demonstrates the potential of these novel composites for practical application in the separation and preconcentration of lead, including radionuclides 210Pb and 210Po, from complex matrices.

Two new copper triethanolamine (tea) complexes, [Cu(tea)(H2O)(2)](SeO4)center dot H2O (1) and [Cu(tea)(H2O)(2)](BeF4)center dot H2O (2) were obtained from aqueous solutions. Their crystal structures are orthorhombic (sp. gr. Pbca) with the following unit cell parameters: a = 12.6763 (2) angstrom, b = 14.9699 (2) angstrom, c = 15.2092 (2) angstrom, V = 2886.14 (7) angstrom 3 (for 1) and a = 12.3858 (2) angstrom, b = 14.8016 (2) angstrom, c = 15.0535 (2) angstrom, V = 2759.75 (7) angstrom 3 (for 2). Both 1 and 2 are full structural analogs of the previously reported [Cu(tea)(H2O)(2)](SO4)center dot H2O sulfate and contain the pseudooctahedral [Cu(tea)(H2O)(2)](2+) cations, tetrahedral TX42- anions and hydration water molecules which form a complex hydrogen-bonded network. The tetrapodal tea ligand and two water molecules form a distorted octahedron around Cu2+ with four relatively short (1.95 - 2.03 angstrom; Cu-N and Cu-O) and two longer (2.30 - 2.38 angstrom; Cu-O) bonds, in agreement to the expected Jahn - Teller distortion for the 3d(9) configuration. The existence of full isostructural series between sulfates, selenates, and fluoroberyllates presents a manifestation of chemical analogy where chemically dissimilar anions ([TO4](2-) vs. [BeF4](2-)) can play identical structure-directing roles. However, this phenomenon is not universal but is governed by strict boundary conditions related to cation properties, anion stability, and synthetic protocol. As in the case of (enH(2))[Cu (H2O)(4)(TX4)](2), the three compounds [Cu(tea)(H2O)(2)](TX4)center dot H2O (TX4 = SO42-, SeO42-, and BeF42-) were found to be isostructural. The key structural feature is the specific chemical environment of the copper-containing complex cation which only weakly interacts (via hydrogen bonding) with the tetrafluoroberyllate anion preserving its integrity.

This article examines the historical development of the Russian Arctic, the current status of Russia’s claims to extend its continental shelf, and the delimitation of maritime boundaries under the United Nations Convention on the Law of the Sea. It also discusses the substantial natural resources of the Far North. The region accounts for one-tenth of global oil production and one-quarter of natural gas output. It contains deposits of solid minerals, including tin, manganese, gold, nickel, lead, platinum, and diamonds. The article traces the history of establishing the Northern Sea Route, from the first expedition seeking a maritime passage to China to projects proposed by M. V. Lomonosov and D. I. Mendeleev, and outlines its contemporary development. The article further considers an emerging dimension of Russia’s Arctic policy: the restoration of strategically important military bases to support both nuclear and non-nuclear capabilities. These measures are aimed at deterring potential aggression and safeguarding Russia’s diverse interests in the region. The authors conclude that the Russian Arctic encompasses key resource, technological, military, and political assets that are critical to the country’s future. The region serves not only as a major center for resource extraction but also as the base for a powerful icebreaker fleet, a hub of industrial activity supporting year-round navigation along the Northern Sea Route, and a locus of infrastructure essential for national defense. The article also addresses and challenges external claims regarding the status of Arctic territories as “common” or “neutral,” as well as allegations concerning environmental degradation.

The 234Th distribution in seawater and on suspended particulate matter is used to determine the particulate organic carbon fluxes. Methods involving coprecipitation from small volumes of seawater with onboard 234Th analysis have become widespread. However, they are poorly applicable in the absence of onboard measuring equipment and at low 234Th concentrations due to low salinity. Therefore, a study was conducted on the efficiency of 234Th sorption from large volumes of seawater with different salinity using sorbents based on manganese dioxide, iron(III) hydroxide, and barium silicate. The high efficiency of most studied sorbents was demonstrated. Based on the obtained data, a method for 234Th sorption from large volumes of seawater using fibrous sorbents unaffected by hydrodynamic resistance was developed. The distribution of 234Th in the surface waters of the Black Sea was studied, and based on this, the sedimentation rates of particulate 234Th in the Black Sea in spring 2022 were determined.

Sorbents based on polyacrylonitrile fiber, containing ferrocyanides of transition metals and manganese oxides (CoMn-PAN and FeMn-PAN) or iron(III) hydroxide (CoFe-PAN) in their structure were obtained, as confirmed by the results of X-ray diffraction and energy-dispersive analyses. The selectivity of the obtained sorbents was investigated, along with their ability to sorb Cs, Ba (as an analog of Ra), P, and Be from various natural media, including river water and seawater with varying salinity of 18.2 and 33.8 ‰. The data show that the sorbents are universal for the recovery of artificial 137Cs and natural radionuclides from the natural environments, including complex salt composition (seawater). Researching the obtained sorbents during marine expeditions confirmed the efficiency of the obtained materials based on transition metal ferrocyanides and manganese oxides (CoMn-PAN and FeMn-PAN) for the sorption of 137Cs, 7Be, 210Pb, 210Po, 226Ra, 228Ra, and 234Th. Additionally, the sorbent based on transition metal ferrocyanides and iron(III) hydroxide (CoFe-PAN) was effective for the sorption of 137Cs, 7Be, 32P, 33P, 210Pb, 210Po, and 234Th. Based on the obtained results, methods for comprehensively determining artificial 137Cs and natural radionuclides using these sorbents were developed.

Interaction between aqueous solutions of imidazole and H2BeF4 resulted in the formation of a new compound, namely, (C3H5N2)3[Be2F7]. The new fluoroberyllate crystallized in a hexagonal symmetry in a non-centrosymmetric group R32 (a = 9.6083(4) & Aring; and c = 15.7796(5) & Aring;). The structure of the new compound contained fully ordered imidazolium cations C3H5N2+ (which is a relatively rare structural phenomenon) and the "diortho" heptafluorodiberyllate anion ([Be2F7]3-), which interacted via hydrogen bonding. The imidazolium cation formed two strong bonds with two different [Be2F7]3- anions, which, in turn, accepted six hydrogen bonds from the six different imidazolium cations. To date, formation of the "diortho" fluoroberyllate anion is rarely reported, and the reported structure is just a second example containing organic cations. In accordance with the non-centrosymmetric character of the structure, the compound is SHG active, yet the response is relatively small.

A new family of organic-inorganic double sulfates formed by 1-methylpiperazinediium cation (C5H14N2 = 1-mppzH2) and inorganic dications, (1-mpipH2)[M(H2O)6](SO4)2 center dot H2O (M = Mg, Mn, Fe, Co, Ni, Zn, and Cd), has been prepared. All compounds are isostructural to each other. Their crystal structure is comprised of inorganic [M(H2O)6]2+ and organic 1-mppzH22+ cations, sulfate anions and hydration water molecules, linked by a complex net of hydrogen bonds into a 3D network. In addition, two side products, (1-mppzH2)(SO4)center dot 2H2O and (1-mppzH2)(HSeO4)2, were observed. The TGA data indicate that thermal decomposition proceeds in several stages, including dehydration. The nature of the final product essentially depends on the nature of the divalent metal dependent on its reducibility and oxo/chalcophylicity. The crystal structures of the double sulfates are discussed in comparison with those containing some structurally related organic diammonium cations. While selenate analogs of these compounds could not be prepared, we predict existence of isostructural or a closely related family with a tetrahedral dianion similar in charge and size, namely tetrafluoroberyllate, which may be of interest to the chemistry of beryllium.

The article examines the synthesis and electrophysical properties of spinel ferrite ZnFe2O4, produced using the sol–gel method with a solid-state finishing process; as well as through classical ceramic technology with mechanochemical activation. The study includes a detailed analysis of the phase composition and crystalline structure using X-ray diffraction; infrared spectroscopy; mass spectrometry; and thermogravimetric and differential thermal analyses. These methods help identify thermal effects and the stages of synthesis. Impedance spectroscopy is used to investigate the electrophysical properties, revealing a significant influence of firing temperature on electrical ionic conductivity. The results show that the electrophysical properties differ based on the synthesis conditions and methods. This suggests potential applications for ZnFe2O4 as a cathode material in metal-ion batteries. The work highlights the importance of optimizing synthesis conditions to achieve high-performance characteristics in electrode materials.

The depletion of global lithium reserves, coupled with the necessity for environmentally sustainable and economically accessible energy storage systems, has driven the development of sodium-ion batteries (SIBs) as a promising alternative to lithium-ion technologies. Among various anode materials for SIBs, hard carbon exhibits obvious advantages and significant commercial potential owing to its high energy density, low operating potential, and stable capacity retention during prolonged cycling. Biomass represents the most attractive source of non-graphitizable carbon from a practical standpoint, being readily available, renewable, and low-cost. However, the complex internal structure of biomass precursors creates significant challenges for precise control of microstructure and properties of the resulting hard carbon materials, requiring further research and optimization of synthesis methodologies. This work reports the synthesis of hard carbon from Sasa kurilensis via pyrolysis at 900 °C and investigates the effect of alkaline pretreatment on the structural and electrochemical characteristics of the anode material for SIBs. Sasa kurilensis is employed for the first time as a source for non-graphitizable carbon synthesis, whose unique natural vascular structure forms optimal hierarchical porosity for sodium-ion intercalation upon thermal treatment. The materials were characterized by X-ray diffraction, infrared and Raman spectroscopy, scanning electron microscopy, X-ray microtomography and low-temperature nitrogen adsorption–desorption. Electrochemical properties were evaluated by galvanostatic cycling in the potential range of 0.02–2 V at a current density of 25 mAhg−1 in half-cells with sodium metal counter electrodes. The unmodified sample demonstrated a discharge capacity of 160 mAhg−1 by the 6th cycle, with an initial capacity of 77 mAhg−1. The alkaline-treated material exhibited lower discharge capacity (114 mAhg−1) and initial Coulombic efficiency (40%) due to increased specific surface area, leading to excessive electrolyte decomposition.

The problem of liquid radioactive waste (LRW) treatment is a key challenge in nuclear energy. This work investigates the immobilization of the high-activity radionuclide 137Cs in ceramic matrices based on cesium-saturated NaY zeolite. Four consolidation methods were compared: cold pressing and sintering (CPS), CPS with microwave heating (MW), hot pressing (HP), and spark plasma sintering (SPS). It was found that the SPS method at 1000 °C and a holding time of 5 min makes it possible to obtain ceramics with the highest functional characteristics: the leaching rate of Cs⁺ ions was 2.3·10-8 g/(cm2·day), microhardness – 619 HV, density – 2.721 g/cm3. The high performance is due to the formation of a homogeneous fine-grained structure with isostructural phases of pollucite CsAlSiO₄ and nepheline Na₈Al₄Si₄O₁₈ of cubic syngony. The HP method also showed a reduction in processing time to 5 min and high microhardness (587 HV), but the leaching rate was two orders of magnitude higher. CPS and MW methods did not lead to a significant improvement in properties compared to SPS. The obtained SPS ceramics meet the requirements of the international standard ISO 6961:1982.

Materials of the 2D zeolite class retain local catalytically active sites and the stability of traditional zeolites but with layered structures. Synthetic and naturally occurring single- and multilayer apophyllite-related compounds are prototypes of advanced industrial materials for use in various technologies. Their surface chemistry allows for functionalization, and these layers serve as fundamental building blocks for zeolitic frameworks. The discovery of the first triple-layer silicate, günterblassite, provided a critical link that established a fundamental crystal–chemical relationship between layered and framework structures in a wide range of micro- and mesoporous minerals and synthetic materials. The most prominent topic in the development of 2D zeolites remains the synthesis and structural characterization of these 2D zeolite structures This review offers a comprehensive overview of the current state of 2D and 3D zeolites constructed based on apophyllite-type layers. In accordance with the terms of modular crystal chemistry, we present a straightforward classification scheme based on the topological and symmetrical distinctions of the layers and provide ways for their stacking, creating a valuable basis for understanding the modular assembly of advanced porous materials.

A mesoporous calcium silicate (CaSiO3) adsorbent was synthesized by alkaline hydrothermal conversion of boric acid production waste (borogypsum). The material demonstrated a high adsorption capacity for Co2+ ions. The capacity reached 220.8 mg/g. It was found that sorption proceeds predominantly via an ion exchange mechanism with the formation of a CaCoSi2O6 precursor. Dense (3.33 g/cm3) ceramic matrices with high compressive strength (481 MPa) and microhardness (~7.54 GPa) were obtained by spark plasma sintering (SPS) at 1 000 °C. The cobalt leaching rate from the matrices was 2.04×10–7 g/(cm2×day). This meets the requirements for solidified radioactive waste.

The paper proposes an original one-stage method using spark plasma sintering technology (SPS) of manufacturing the ionizing radiation source (IRS) of closed type with a non-dispersible ceramic core based on pollucite obtained using aluminosilicate raw materials saturated (24.3 wt%) with cesium, and doped with 10-40 wt% CsCl. According to the XRD, EDX, AAS and DTA-TG data, optimal conditions for hydrothermal synthesis zeolite NaA were established, the consolidation kinetics and phase transformations into ceramic pollucite under SPS conditions were studied. The ceramics had a relative density of 99.8 % and mechanical strength up to 732 MPa, a low rate of cesium leaching 10-7 g/cm2 day and thermal resistance in air up to 1000 degrees C. It was confirmed by SEM and EDX that the destruction and deformation of pollucite ceramics in the composition with CsCl and steel at the boundary of their contact in the design of the IRS product was absent and diffusion of cesium outside the ceramics did not occur. The achieved cesium content in the ceramic core of the resulting the ionizing radiation source, which meets high quality and regulatory requirements, is 44.3 wt%. The results of the study may be promising for the manufacture of industrial products.

For the first time, new sorbents based on polyacrylonitrile (PAN) fiber and transition metal ferrocyanides were obtained. The main difference between the obtained sorbents and the existing ones is the stage of preliminary preparation of the initial support by converting it into the forms PAN-Fe(OH)3 or PAN-MnO2, due to which additional ion exchange groups (carboxyl, carbonyl, etc.) are formed, which increases the amount of ferrocyanide fixed to the support. The best components and conditions for the synthesis of new sorbents were determined (concentration (0.1–0.2 mol/L), as well as pH (1 for sorbents based on PAN-Fe(OH)3, and 1–5—PAN-MnO2) of potassium ferrocyanide solution, concentration of transition metal salts (0.02 mol/L), temperature conditions). The influence of the studied solution composition (pH, concentration of Na+, K+, NH4+ ions) on the cesium distribution coefficients during its recovery by the obtained sorbents was assessed. The possibility of cesium recovery from solutions with pH 1–9 containing macro quantities of cations was demonstrated. The sorbents derived were characterized by modern structural methods such as infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy with EDS analysis. A study of the trace amount sorption of 137Cs was carried out in comparison with commercially available highly efficient sorbents (FNS-10 and Termoksid-35), and it was shown that the resulting sorbents are not inferior to industrial ferrocyanide sorbents and can be used for 137Cs selective sorption from technological solutions and natural waters.

Two new organo-inorganic hybrids, (C2N2H10)[Cu(H2O)4](BeF4)2 (1) and (C2N2H10)[Cu(H2O)4](SeO4)2 (2), were prepared via the interaction of ethylenediamine, copper fluoroberyllate or selenate, and H2[BeF4]/H2SeO4 in aqueous solutions. The structures of 1 and 2 are similar to each other and the previously reported (C2N2H10)[Cu(H2O)4](SO4)2: monoclinic, P21/c, a = 5.1044(2) Å, b = 11.6171(4) Å, c = 10.1178(3) Å, and β = 94.431(3)° for 1; and a = 5.25020(10), b = 11.7500(2), c = 10.4434(2), and β = 94.5464(17)° for 2. All structures contain a square planar [Cu(H2O)4]2+ species, which coordinates, at rather long distances, two TX42− tetrahedral dianions in κ1 mode, forming relatively weak [Cu(H2O)4(TX4)2]2− complexes. These are linked together via hydrogen bonding into pseudo-chains; the ethylenediammonium cations link them into a 3D architecture. Compound 1 is, to the best of our knowledge, the first—though expected—representative of a hybrid organo-inorganic fluoroberyllate. The crystal chemical relations within the structural family (enH2)[Cu(H2O)4](TX4)2 are discussed.

Zeolites have become promising adsorbents for wastewater treatment due to their enhanced adsorption capacity, stability of crystalline structure, high porosity and surface area. One of the primary goals of our study was to assess the effectiveness of employing NaY zeolite as a sorbent and potential solid matrix for immobilizing radionuclides. In this study NaY faujasite zeolite was obtained by hydrothermal synthesis and characterized by X Ray diffraction (XRD), N2 adsorption-desorption, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) methods. The prepared zeolite had NaY faujasite crystalline structure, characterized by developed surface area (370 m2/g) with micro-mesoporous structure, and spherical-like morphology with particles of 1-4 mu m in diameter. The isotherms adsorption modeling on Cs+, Sr2+, Co2+, Pb2+ and La3+ ions was performed. The isotherm well described by Langmuir equation with maximum adsorption capacity of q(Cs+) = 1,9 mmol/g, q(Sr2+) = 3,75 mmol/g, q(Co2+) = 1,82 mmol/g, q(Pb2+) = 2,54 mmol/g, q(La3+) = 3,83 mmol/g. Thermal behavior of metal-saturated adsorbents by differential thermal analysis (DTA) and thermal gravimetric (TG) techniques was studied. Each metal examined in this paper is responsible for the stable formation of radionuclides (137Cs, 90Sr, 60Co, La generally, the group of active lanthanides was modelled, Pb uranium fission residues) that are generated during the operation of nuclear power plants. To optimize sintering regimes, it has been proposed to achieve sorption saturation of stable ions such as Cs, Sr, Co, La, and Pb and transfer them into solid matrices. It was shown that the consolidation temperature for the obtained samples varies in the range of 935-1040 degrees C.

A series of (2–carbamoyl ethyl)diphenylphosphine oxides (KFO) has been synthesized from commercially available reagents — diphenyl chlorophosphine and acrylamides. The influence of the number of ligand fragments of Ph2P(O)(CH2)2C(O), the nature of the oligoyl radical binding these fragments, as well as the presence of additional coordination centers in the KEFO molecule on the extraction properties of KEFO with respect to actinides and lanthanides was investigated. It was found that N,N′-methylene-bis[3-(diphenylphosphoryl) has the greatest efficiency in the extraction of actinidespropionamide] (III), in which two diphenylphosphorylpropionyl radicals are bound by a rigid HNCH2NH linker (the degree of extraction of U(VI) reaches ~73%, and Th(IV) — ~85%), while in the case of lanthanides, on the contrary, ligand V, containing the maximum amount of this kind of phosphoryl carbonyl radicals attached to a conformationally non-rigid nitrogenous heterocyclic matrix, as well as KEFO (II), containing an additional C=O group in an alkyl radical attached to a nitrogen atom, has significant advantages carbamoyl fragment (when using this compound, gadolinium extraction is close to 92%). The obtained data show that highly effective and selective extractants of both 4fand 5felements can be created on the basis of (2-carbamoyl ethyl)diphenylphosphine oxide structure.

A mesoporous adsorbent based on calcium silicate CaSiO3 for the removal and immobilization of cobalt Co-60 radionuclides in durable ceramic CaCoSi2O6 matrices was synthesized by hydrothermal conversion of boric acid production waste. The obtained material had a high Co2+ ions adsorption capacity of 220.8 mg/g. Cobalt adsorption was carried out mainly by ion exchange, which led to the formation of CaCoSi2O6 precursor ceramic matrices. The use of spark plasma sintering (SPS) technology at an optimal temperature of 1000 degrees C allowed the safe immobilization of Co2+ ions in CaCoSi2O6 ceramic matrices characterized by density (3.33 g/cm(3)), compressive strength (481 MPa) and microhardness (similar to 9.81 GPa). Sintered CaCoSi2O6 ceramic samples were characterized by high hydrolytic stability (cobalt leaching rate R-Co similar to 10(-7) g/(cm(2) x day)) and complied with the requirements for cured highly active waste GOST R 50926 96/ANSI/ANS 16.1.

The patterns of cesium recovery under static and dynamic conditions with new ferrocyanide sorbents based on pre-prepared polyacrylonitrile (PAN) fiber by converting the latter into PAN-MnO2 or PAN-Fe(OH)3 modifications were studied. Optimal sorption conditions for the obtained sorbents were determined. The dependence of cesium recovery degree on the sorption time was characterized using kinetic models of pseudo-first and pseudo-second order, the Elovich model, and also dependence of the sorbent capacity on the equilibrium concentration of cesium in solution using Langmuir and Freundlich isothermal models. It was found that sorption equilibrium is achieved in 8–20 h. Maximum capacity is achieved at the equilibrium concentration of cesium in the solution of more than 1500 mg L–1. The output sorption curves were constructed, based on which the dynamic (0.88–3.67 mg g) and total dynamic exchange capacities (15.5–26.9 mg g) of the obtained sorbents were determined. The desorption and kinetics of cesium desorption have been studied, and the best desorption agents and the optimal desorption time have been found out. During the marine expeditionary research, the high efficiency of 137Cs recovery (> 80