Open Access
Access granted
Subscription Access
Vol 70, No 9 (2025)
СИНТЕЗ И СВОЙСТВА НЕОРГАНИЧЕСКИХ СОЕДИНЕНИЙ
PHOTOELECTROCHEMICAL DEGRADATION OF IBUPROFEN ON A TITANIUM DIOXIDE NANOTUBE PHOTOANODE
Abstract
Titanium dioxide nanotube photoanodes were obtained by anodizing titanium foil at 60 V in an ethylene glycol-based electrolyte using a two-stage scheme with intermediate removal of the amorphous coating and subsequent annealing at 450 °C. The nanotubes consist of titanium dioxide in the form of anatase and have a length of 20–22 μm, an average diameter of 90–100 nm and a wall thickness of 20 nm. The activity of such a photoanode in the reaction of photoelectrochemical oxidation of ibuprofen (IBP) in the molecular and ionic form of potassium salt of 2-(4-isobutylphenyl)-propionic acid (2-(4-IBFPA) was studied. Regardless of the form of IBP, its photoelectrocatalytic oxidation on titanium dioxide nanotubes occurs with the intermediate formation of oxygenated forms of IBP. The results of intensity modulated photocurrent spectroscopy (IMPS) show that the addition of IBP to the 0.9% NaCl solution helps to suppress the recombination of electron-hole pairs due to the increased rate of charge transfer to the IBP. The TNT/Ti photoanode showed stable operation in the process of long-term photoelectrooxidation of IBP.
Russian Journal of Inorganic Chemistry. 2025;70(9):1099-1106
1099-1106
AMORPHOUS AND CRYSTALLINE TITANIUM-AMMONIUM PHOSPHATES: SYNTHESIS, PHOTOCATALYTIC AND PHOTOPROTECTIVE PROPERTIES
Abstract
Amorphous and crystalline titanium-ammonium phosphates Ti2O2H(PO4)[(NH4)2PO4]2 were synthesized by the hydrothermal method. It is shown that the minimum temperature and processing time for the crystallization of the Ti2O2H(PO4)[(NH4)2PO4]2 phase are 160°C and 12 hours, respectively. At the same time, NH4
+ and PO4
3− ions are present in X-ray amorphous samples, similar to the crystalline compound, and during crystallization, a decrease in the content of water or hydroxyl groups and an increase in molar ratio of P : Ti are observed. X-ray amorphous samples consist of isotropic particles 10–15 nm in size, while crystalline samples contain rhombus-shaped plates with smaller primary particles in their structure. X-ray amorphous and crystalline titanium-ammonium phosphates have low photocatalytic activity. The sun protection factor of X-ray amorphous samples, determined according to the international standard ISO 24443, is comparable to the sun protection factor of commercially available titanium dioxide.
Russian Journal of Inorganic Chemistry. 2025;70(9):1107-1115
1107-1115
SYNTHESIS, STRUCTURE AND THERMAL PROPERTIES OF SILICOPHOSPHATES OF ZIRCONIUM AND ALKALI METALS (K, Rb, Cs)
Abstract
Silicophosphates A2Zr2SiO4(PO4)2 (A = K, Rb, Cs) with langbeinite mineral structure have been synthesized and investigated for the first time. The samples were characterized using XRD, IR spectroscopy, SEM and energy dispersive X-ray microanalysis. Single-phase silicophosphates were obtained at 800°C. Using the Rietveld method to clarify the crystal structure of Rb2Zr2SiO4(PO4)2 revealed that it is based on a three-dimensional framework composed of ZrO6 octahedra and (Si/P)O4 tetrahedra, with extra-framework alkali metal cations occupying isolated cavities. The stretching and deformation vibration bands of the SiO4- and PO4- tetrahedra were determined for these compounds. Correlations were revealed between the IR spectra and the nature of the A+ cation. The thermal stability of the silicophosphates up to 1200°C was confirmed by thermal X-ray diffraction and combined TG-DSC analysis. The linear thermal expansion coefficient of Cs2Zr2SiO4(PO4)2 was found to αa = 5.8 × 10−6 °C−1. The results obtained allow us to conclude that the studied silicophosphate materials are highly adapted to extreme temperature conditions.
Russian Journal of Inorganic Chemistry. 2025;70(9):1116-1126
1116-1126
A NEW VIEW ON HETEROVALENT ISOMORPHIC SUBSTITUTION OF Zr4+ IN Na3Zr2Si2PO12 BY TRIVALENT ELEMENTS
Abstract
The partial substitution of Zr4+ in siliconposphate Na3Zr2Si2PO12 by a trivalent element has been investigated in this work. On the example of Fe3+-substituted NASICON it is shown that the formed complex does not correspond to the generally accepted formula Na3+y
M(III)yZr2-y
Si2PO12, in which electroneutrality of the obtained composition is achieved by charge compensation by additional Na+ ions. The formation of Na3M(III)yZr2-y
Si2-y
P1+y
O12 complexes was established on the basis of X-ray phase analysis, scanning electron microscopy and refinement of crystal lattice parameters by the Rietveld method. The precursor composition Na3+y
M(III)yZr2-y
Si2PO12 is excessive in Na and Si for the Fe-substituted complex. Elements that are superstoichiometric for the new crystal lattice are partially incorporated into the main NASICON phase, increasing the parameters of the unit cell, and partially participate in the formation of additional phases: amorphous or crystalline. The amorphous phase is formed at grain boundaries of low dopant compositions. Impurity crystalline phases are formed in high dopant compositions.
Russian Journal of Inorganic Chemistry. 2025;70(9):1127-1137
1127-1137
Synthesis of nanosized SnO2 via chemical precipitation followed by hydrothermal treatment using tin(II) acetate
Abstract
The paper studies the synthesis process of nanosized tin dioxide obtained by a combination of direct chemical precipitation and hydrothermal treatment using tin(II) acetate as a precursor. A comparative analysis of the chemical composition, microstructure and crystal structure of the samples obtained under different conditions is performed. Thus, the thermal behavior of the obtained powders in the temperature range of 25–1000°C was studied using synchronous thermal analysis (TGA/DSC); the set of functional groups in the powders was studied using IR spectroscopy; X-ray diffraction analysis (XRD) was used to study the crystal structure of the powders and determine the size of the coherent scattering region. Using scanning electron microscopy (SEM) and transmission electron microscopy (TEM), the effect of hydrothermal treatment on the size of primary particles and agglomerates formed on their basis is shown. It was found that during hydrothermal treatment, the primary particles enlarge from 2.2 ± 0.4 to 2.6 ± 0.6 nm, while the microstructure of the samples becomes more uniform and the size of the agglomerates decreases from 42 ± 12 to 40 ± 8 nm. The morphology of the films formed using the obtained nanopowders was studied using atomic force microscopy (AFM). Within the framework of AFM, Kelvin probe force microscopy (KPFM) was used to construct surface potential distribution maps, as well as to estimate the electron work function from the surface of the materials.
Russian Journal of Inorganic Chemistry. 2025;70(9):1138-1147
1138-1147
ANALYSIS OF CLOSO-DECABORATE ANION AND ITS DERIVATIVES BY CAPILLARY ZONE ELECTROPHORESIS
Abstract
Boron cluster compounds are inorganic polyhedral structures used in various fields, they have a wide range of different types of bioactivity and are perspective compounds for boron neutron capture therapy of cancer. Therefore, they require the development of various analytical techniques for qualitative and quantitative analysis and determination of their properties. Capillary electrophoresis (CE) is an interesting, universal method for analysis of charged substances. However, there is a fairly limited number of boron cluster compounds studies using CE. Here reports the possibility of a technically simple method of capillary zone electrophoresis analysis of boron clusters [B10H10]2− and some of its derivatives, as well as the [B12H12]2−. The possibility of anions analysis in normal and reverse polarity separation modes in the absence of capillary surface modifiers or capillary wall polymer coating has been demonstrated. Electrophoretic mobilities were determined for analyzed compounds. The presented work is a clear example of the fact that capillary electrophoresis can serve as a simple and convenient method for soluble and partially water-soluble boron cluster compounds analysis.
Russian Journal of Inorganic Chemistry. 2025;70(9):1148-1156
1148-1156
КООРДИНАЦИОННЫЕ СОЕДИНЕНИЯ
SYNTHESIS, STRUCTURE, AND OPTICAL PROPERTIES OF CYCLOMETALATED IRIDIUM(III) COMPLEXES WITH 1,2-DIPHENYLBENZIMIDAZOLE AND N-SUBSTITUTED PERIMIDINES
Abstract
Two novel bis-cyclometalated iridium(III) complexes with 1,2-diphenylbenzimidazole (pbi) and ancillary 1-methyl-2-(pyridin-2-yl)-1H-perimidine (L1, complex 1) and ethyl 2-(2-(pyridin-2-yl)-1H-perimidin-1-yl)acetate (L2, complex 2) were synthesized and characterized by set of physicochemical methods. Comparison of the results of crystal packing analysis and electronic absorption spectroscopy demonstrates that while exclusion of the rigid perimidine system from conjugation does not allow red-shifting of absorption maxima, both complexes exhibit broad absorption up to 600 nm (ε = 27 000 − 800 M-1 cm-1), comparable to iridium analogs. The results of the study clarify the influence of steric factors on the absorption properties of the complexes and will be used for further development of strongly light-absorbing materials.
Russian Journal of Inorganic Chemistry. 2025;70(9):1157-1164
1157-1164
ФИЗИЧЕСКИЕ МЕТОДЫ ИССЛЕДОВАНИЯ
Thermodynamic characteristics of gaseous iron(IV) fluoride
Abstract
A critical review of studies on attempts to synthesize FeF4 molecules and mass spectrometric investigations of the presumed equilibria of reactions involving them does not provide a definitive answer regarding the existence of this compound. However, when combined with the results of IR spectroscopy studies in inert gas matrices and quantum-mechanical calculations, reliable values can be recommended for the bond dissociation energy D
0(FeF3–F) = 194.6 ± 8.0 kJ/mol and the standard enthalpy of formation of gaseous iron(IV) fluoride Δf
H°(FeF4, 0) = −847.2 ± 7.5 kJ/mol. A comparison with the thermodynamic characteristics of similar tetrafluorides is presented.
Russian Journal of Inorganic Chemistry. 2025;70(9):1165-1171
1165-1171
ФИЗИКО-ХИМИЧЕСКИЙ АНАЛИЗ НЕОРГАНИЧЕСКИХ СИСТЕМ
HEAT CAPACITY AND THERMODYNAMIC PROPERTIES OF COMPLEX OXIDES WITH β-PYROCLORE STRUCTURE CsTeMoO6 AND CsV0.625Te1.375O6
Abstract
The heat capacity of complex oxides with β-pyrochlore structure CsTeMoO6 and CsV0.625Te1.375O6 was investigated by adiabatic vacuum and differential scanning calorimetry in the temperature range of T = 5–500 K. The standard thermodynamic functions: heat capacity Cp
o
, enthalpy [H°(T)−H°(0)], absolute entropy [S°(T)] and the Gibbs energy [G°(T)−H°(0)] for the range from T → 0 to 500 K were calculated based on the obtained experimental data. The low-temperature (T < 50 K) heat capacity dependence was analyzed on the basis of multifractal model and chain-layered structure topology of the studied compounds was established.
Russian Journal of Inorganic Chemistry. 2025;70(9):1172-1179
1172-1179
ФИЗИКОХИМИЯ РАСТВОРОВ
INFLUENCE OF THE PROPORTION AND TYPE OF FUNCTIONAL GROUPS ON THE SELECTIVE PROPERTIES OF MODIFIED POLY-3-AMINOPROPYLSESQUIOXANES TOWARD SILVER(I)
Abstract
The effect of the proportion and type of functional groups on the selective properties of modified poly(3-aminopropylsilsesquioxanes) in silver(I) extraction from multicomponent aqueous solutions was studied. The sorbents were obtained by modifying poly(3-aminopropylsilsesquioxane) with sulfur-containing reagents at different temperature conditions, which allowed varying the ratio of monosubstituted and disubstituted thiourea groups, as well as amino groups. The sorbent structure was determined by IR spectroscopy and elemental analysis. It was found that an increase in the proportion of monosubstituted thiourea groups (from 40 to 75%) in the sorbent structure led to an increase in the degree of extraction and selectivity with respect to silver(I) in the pH range of 1–4. The introduction of an additional heating stage promotes the formation of a larger number of monosubstituted groups. Sorption of accompanying metal ions (copper(II), calcium(II), magnesium(II)) is minimal in a wide pH range. The obtained results allow us to purposefully regulate the sorption and selective properties of materials by varying the ratio of functional groups on the surface of the sorbent.
Russian Journal of Inorganic Chemistry. 2025;70(9):1180-1187
1180-1187
НЕОРГАНИЧЕСКИЕ МАТЕРИАЛЫ И НАНОМАТЕРИАЛЫ
Growth characteristics, phase composition and optical properties of Ti–Sc–O thin films synthesized by atomic layer deposition
Abstract
Ti–Sc–O thin films were synthesized at 300°C by atomic layer deposition (ALD) via alternating between the reaction cycles with metal precursors and H2O as co-reactant. By varying the cycle ratio, the materials of [Sc]/([Ti] + [Sc]) = 13, 25, 44, 64, 82% were obtained. The films were examined via spectral and single wave null ellipsometry, X-ray photoelectron spectroscopy, scanning electron microscopy and X-ray diffraction. The formation of the material was demonstrated to be substrate-inhibited and to occur within the “temperature window” of ALD. As a result of Ti2p and Sc2p XPS spectra analysis, the oxidation states of the metals are Ti4+ and Sc3+. At low Sc concentrations (up to [Sc]/([Ti] + [Sc]) = 25%) the film crystallization into anatase phase observed for individual TiO2 film is suppressed. In the range of [Sc]/([Ti] + [Sc]) = 44–100% the materials of various cubic crystal structure types are formed: with the increase of scandium concentration the structure changes from disordered fluorite Sc4Ti3O12 to cubic Sc2O3-based solid solution. The refractive indices n(E), extinction coefficients k(E) and optical bandgap values are well described by the Tauc-Lorentz model. They vary between the corresponding parameters of the individual oxides depending on the composition, which is relevant for current problems of optics, photonics, solar energy and photocatalysis.
Russian Journal of Inorganic Chemistry. 2025;70(9):1188-1200
1188-1200
INFLUENCE OF SILVER PRECURSORS INTRODUCING METHOD ON PROPERTIES OF MAGNETICALLY RECOVERABLE Ag/FeOx CATALYSTS IN 4-NITROPHENOL REDUCTION
Abstract
The conducted study aims to compare the properties of magnetically recoverable Ag/FeOx catalysts obtained by different synthesis approaches (impregnation, coprecipitation, and impregnation of the pre-reduced support), and to test their activity in 4-nitrophenol reduction in aqueous solution at room temperature. The most active catalysts in 4-nitrophenol reduction are the samples obtained by impregnation with Ag precursors of the pure support (k = 2.19 min−1) and the pre-reduced one in H2/Ar flow at 250°C (k = 3.21 min−1). This is due to the in situ formation of dispersed and active Ag particles from the cationic precursor under the reducing agent NaBH4 exposure. The nature of the Ag precursors (Ag+ or Ag(NH3)2
+) affects Ag particles' activity. The catalysts in which the ammonia complex Ag(NH3)2
+ was used as the silver precursor exhibit lower activity compared to samples in which AgNO3 was used. Differences in thermodynamics and kinetics of Ag+ or Ag(NH3)2
+ to Ag0 reduction determine the morphology and dispersion of metallic silver particles, which affects the activity of the resulting catalysts. The presence of magnetic properties in the catalyst samples is shown by the exposure of an external magnetic field.
Russian Journal of Inorganic Chemistry. 2025;70(9):1201-1216
1201-1216
SYNTHESIS OF THE STABLE NiFe2O4 AND NiFe2O4/Au HYDROSOLS USING POLYETHYLENIMINE
Abstract
In this study, the effect of reaction parameters on the stabilization of nickel ferrite hydroxols in the presence of polyethylenimine (PEI) was determined using the design of experiment (DOE) method. In the optimal conditions, a nickel ferrite hydroxol was obtained, and its sedimentation stability was maintained for two months. A NiFe2O4/Au hybrid material was obtained by adsorbing on the surface of magnetic gold particles and reducing Au(III) by hydroxylamine in the presence of PEI, over four steps. Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) show the NiFe2O4/Au material is Au0 nanoparticles 4 nm in size and uniformly distributed on the surface of ferrite nickel nanoparticles 9.7 nm in size. The gold particles are firmly attached to the surface of nickel ferrite and do not separate during post-synthetic and ultrasonic treatment. Besides their content can be controlled by adjusting the number of gold reduction stages.
Russian Journal of Inorganic Chemistry. 2025;70(9):1217-1228
1217-1228