In the presented work, heterostructured nanocomposites based on g-C₃N₄ and PrFeO₃ with different mass content of PrFeO₃ (0–10 wt%) were prepared by ultrasonic processing to study their photocatalytic activity in the process of antibiotic degradation under visible light. The study of phase composition, structural, morphological and textural characteristics carried out by powder X-ray diffraction, scanning electron microscopy and adsorption-structural analysis confirmed the presence of two phases - graphite-like C₃N₄ and orthorhombic PrFeO₃ with average crystallite sizes of 5 and 21 nm and mesoporous structure with specific surface area of 57.2–68.6 m²/g and average pore size of 20 nm. The measured values of the forbidden bandwidth for the obtained nanocomposites were ∼3 eV, indicating potential activity under visible light irradiation. The efficiency of antibiotic removal under visible light was evaluated in the degradation of TCHCl. It was found that 5 % PrFeO₃ content was optimal and increased the TOF by 5 times compared to pure g-C₃N₄. The results of photocatalytic test with absorbers showed that photocatalysis occurs by Z-scheme mechanism. The results obtained allow us to consider this nanocomposite as an effective and stable photocatalyst for pharmaceutical wastewater treatment.

A series of finely dispersed Y ₂ O ₃ :Eu and YAG:Eu phosphors useful for the enhancement of photodynamic therapy (PDT) of cancer were prepared using the Pechini method and self-propagating high temperature synthesis (SHS). The obtained phosphors can be used in cancer therapy drugs in combination with a photosensitizer which accumulates selectively in tumor tissues. Upon excitation with X-ray irradiation which easily penetrates the organism such phosphors are activated to radiate the visible light with wavelengths required to stimulate the photosensitizer yielding active singlet oxygen which destroys cancer cells. Thus the developed phosphors provide an extension of PDT in the treatment of internal tumors which are inaccessible for activating light from the outside. A detailed characterization of the obtained phosphors was performed to define various types of adsorption centers and the functional groups on their surface, including hydroxyls with different acid-base characteristics and an admixture hydrated carbonate layer which may help in linking with other drugs (photosensitizer and pluronic binder) and is important in respect of biocompatibility. A model describing the composition of acid-base centers with various pK _a values on the surface of the studied materials is suggested on the basis of the obtained results as an approach to study the adjustable modification of various compounds in respect of the compatibility between their ingredients as well as their overall biocompatibility. Y ₂ O ₃ :Eu phosphor prepared via the SHS method was successfully tested for biological (therapeutic) activity which provided an effective destruction of fibroblast cell cultures of Chinese hamster V-79 in combination with a photosensitizer upon X-ray irradiation.

Photo-Fenton-like oxidation of organic substances is one of the key advanced oxidation processes based on the reversible Fe2+↔Fe3+ transition and the generation of a strong oxidant ·OH in the presence of H2O2 and is currently considered as a promising method for the purification of polluted aqueous media. However, the absence of effective and stable photocatalysts of this process, operating under the action of visible light, necessitates the exploratory studies, mainly among iron oxides and ferrites of various compositions and structures. In this work, using the method of solution combustion followed by heat treatment in air the heterojunction nanocomposites based on ytterbium orthoferrite and cerium dioxide of the composition o-YbFeO3/h-YbFeO3/CeO2 (0–20 mol.%) with high absorption in the visible region and advanced photo-Fenton-like activity were obtained. The nanocomposites were studied by EDS, SEM, XRD, BET, and DRS methods. The photo-Fenton-like activity of the nanocomposites was investigated during the degradation of methyl violet under the action of visible (λmax = 410 nm) radiation. As a result, the formation of I-type heterojunction based on stable rhombic (55.4–79.0 nm) and metastable hexagonal (19.5–24.0 nm) modifications of ytterbium orthoferrite (o-YbFeO3 and h-YbFeO3, respectively) and cubic cerium dioxide CeO2 (13.2–19.2 nm) nanocrystals was established. It was shown that the obtained nanocomposites had foamy morphology and were characterized by a specific surface in the range of 9.1–25.0 m2/g, depending on the CeO2 content. It was found that nanocrystalline components were chemically and phase-pure, uniformly spatially distributed over the nanocomposite, and had multiple contacts with each other. Based on this fact and the established electronic structure of the nanocomposite components, the formation of I-type heterojunction with the participation of o-YbFeO3 (Eg = 2.15 eV), h-YbFeO3 (Eg = 2.08 eV), and CeO2 (Eg = 2.38 eV) was shown, the presence of which increased photocatalytic activity of the resulting nanocomposite. The optimal content of CeO2 in the nanocomposite was 5%, and the o-YbFeO3/h-YbFeO3/CeO2–5% sample was characterized by the highest rate constant of photo-Fenton-like degradation of methyl violet under the action of visible light equal to k = 0.138 min–1, which was 2.5 to 5 times higher than for nanocomposites based on ytterbium orthoferrite. The obtained results obtained indicate that the developed nanocomposites can be considered as a promising basis for the advanced oxidation processes for the purification of aqueous media from organic pollutants.

The work proposes the use of aluminum oxide-based ceramic objects with a TPMS-Q-surface geometry as elements of armor structures. The samples were produced using the SLA-DLP 3D printing method. The main properties of the sample were determined using physical-chemical analysis methods: apparent density ρ_ap = 3.6 g/cm³, open porosity P_opn = 8.5%, microhardness H_µ = 15.3 GPa, water absorption W = 2.4%, elastic modulus E = 405 GPa. The Stiglich criterion M = 1.72 EPa²·m³/kg, and the Shevchenko criterion K = 0.8.

Ферриты играют важную роль в ряде отраслей от магнитных керамических материалов до мультифункциональных каталитических и антимикробных материалов. Катализатору крайне важно иметь не только высокую активность, но и быть изготовленным из распространённых элементов с помощью энергоэффективных технологий, чтобы сделать его применимым для промышленного внедрения. Серию нанокристаллических порошков магнезиоферрита получили методом растворного горения при варьировании соотношения топливо/окислитель. Образцы исследовали с помощью методов рентгенофазового анализа, адсорбционно-структурного анализа, сканирующей электронной микроскопии, спектроскопии диффузного отражения и испытали их активность в Фентоно-подобной фотокаталитической реакции. Были измерены температурно-временные профили реакции горения всех смесей. Результаты показывают сильную корреляцию между содержанием топлива и температурой, структурой и морфологией. Но, несмотря на меньшую удельную площадь поверхности и больший размер кристаллитов среди образцов серии, образец, синтезированный с избытком топлива, показал наиболее высокую степень адсорбции красителя и каталитическую...