The results of a study of the influence of the thickness of porous glass (PG) plates modified with zinc oxide on its photocatalytic properties and ability to photogenerate oxygen in aqueous media are presented.

Composite materials (CMs) based on matrices of high-silica porous glasses activated by Cu2+ and Y3+ ions are synthesized. The influence of the composition of composites (concentration and ratio of copper and yttrium introduced) and the temperature of their heat treatment (in the range of 50–870°C) on their spectral properties is studied. Examining samples using optical and IR spectroscopy reveals absorption bands related to Cu2+ ions and caused by vibrations of the Y–O bonds in Y2O3. It is established that, depending on the synthesis conditions, the obtained materials possess UV, blue-green, and IR luminescence due to the presence of various active centers (defects and oxygen vacancies in CuO, Cu2+ ions, radicals , and F centers in Y2O3, =Si0 centers, E' centers (O3≡ Si· ), neutral oxygen vacancies (O3≡Si–Si≡O3), and nonbridging oxygen defect centers in the silica matrix of glass.

Bismuth-containing composite materials (CMs) with variable yttrium oxide content are synthesized by impregnating porous silicate glass matrices in acidified aqueous-salt solutions of Bi(NO3)3·5H2O in the presence of Y(NO3)3·6H2O with their subsequent heat treatment at 650 or 870°C, and their luminescent properties are studied. It is found that the synthesized materials exhibit photoluminescence in a wide spectral range (230–900 nm) due to the presence of various active centers (=Si0, Y3+– O_3^2 - , Si-BAC (silicon-associated bismuth active centers), radicals , Bi3+ and Bi2+ ions, Bi3+ pairs, silicon–oxygen defects), as well as the Bi3+ → Y3+ MMCT (metal-to-metal charge transfer) transition, as a result of which they can be considered as new promising solid-state phosphors.

A methodology is developed and ZnO nanoparticles are synthesized in porous glasses. The synthesis is carried out by impregnating silicate porous glasses in an aqueous solution of zinc nitrate and its subsequent thermolysis. The spectral and luminescent properties of the synthesized composites are studied. The ability of ZnO nanoparticles formed in porous glass to produce reactive oxygen species under UV irradiation is studied.

Разработана методика, и синтезированы наночастицы ZnO в пористых стеклах. Синтез проведен путем пропитки силикатных пористых стекол в водном растворе нитрата цинка и его последующего термолиза. Исследованы спектрально-люминесцентные свойства синтезированных композитов. Изучена способность наночастиц ZnO, сформированных в пористом стекле, к выработке активных форм кислорода при УФ-облучении.

The article presents the results of a study of the optical properties of cesium-containing quartzoid glasses (QG NFF-Cs) obtained as a result of the heat treatment of high-silica porous glasses (PGs) impregnated with aqueous solutions of CsNO3. It is established that the introduction of cesium into the composition of high-silica quartz glasses (QG NFF) led to the emergence of absorption bands at 332, 384, 388, 442, 492, 565, 567, 583, 586, 621, 635, 695, 696, and 703 nm, which are related to the absorption of cesium atoms. The introduction of cesium into the composition of the glass leads to a decrease in the absorbance QG NFF-Cs by 15–20

Composite materials (CMs) based on matrices of high-silica nanoporous glasses activated by silver and lanthanum are synthesized. It is established that, depending on the composition, the CM samples exhibit luminescence in the UV, violet-blue, green, red, and infrared spectral ranges due to the presence of isolated Ag+-ions, Ag+–Ag+ paired centers, molecular clusters (MCs) and nanoparticles (NPs) of silver, and oxygen vacancies in La2O3, together with various silicon defect centers.

A methodology for the formation of molecular clusters of silver in silicate nanoporous glasses has been developed. Composite materials containing molecular clusters of silver, silver nanoparticles and zinc oxide have been synthesized. The synthesis was carried out by impregnation of porous glasses in aqueous solutions of silver and zinc nitrates stabilized with high-molecular polyvinylpyrrolidone, followed by heat treatment of samples for decomposition of metal nitrates and polymer. Spectral-luminescent properties of composites have been investigated. Keywords: porous glass, zinc oxide, silver molecular clusters, silver nanoparticles, spectral-luminescent properties.

Bismuth containing porous glasses (BPGs) were prepared on the basis of high-silica micro- and macroporous glasses and also of microporous glasses thermally treated at 750°C. The chemical composition of the glasses was determined by standard analytical methods and X-ray fluorescence analysis. Energy dispersive X-ray analysis showed that bismuth is predominantly formed at the half-thickness of the membranes. Characterization of the glass morphology was carried out by scanning electron microscopy. Their structural properties (specific surface area, volume porosity, structural resistance coefficient, average pore radius) and electrosurface ones (specific electrical conductivity, transport numbers of ions in the pore channels, electrokinetic potential) were studied in 10 −4 –10 −1 M KNO 3 solutions in a neutral pH range. The results were compared with similar properties of PG membranes not modified with bismuth(III) oxide. Porous glasses doped with bismuth oxide were found to restore their electrosurface characteristics in the neutral pH range in the concentration range of KNO 3 solutions under study.

Composite materials (CMs) based on porous glass matrices activated by yttrium in the presence of copper or bismuth are synthesized. It is established that, depending on the composition, the CM samples exhibit UV, blue-green, red, and infrared luminescence due to the presence of various centers, including Bi3+ and Cu+ ions, F centers in Y2O3, and molecular ions O_3^ - 2 associated with cation vacancies Y3+.

The spectral-optical and luminescence properties of bismuth-containing composite materials based on matrices of high-silica porous glasses are investigated. Luminescence spectra, luminescence excitation spectra, infrared transmission spectra (8000–4000 cm-1) depending on the composition of different types of matrices and sintering atmosphere (nitrogen, argon) of bismuth-containing composite materials were examined. It was found that the samples of bismuth-containing composite materials are characterized by UV (λem = 350 nm), blue-green (λem = 410–550 nm) and orange-red (λem = 600–725 nm) luminescence due to the presence of various bismuth active centers. The analysis of the spectra obtained by near-infrared spectroscopy demonstrates the formation of Bi2+ dimers of bismuth and bismuth active centers associated with silicon.

A methodology for the formation of molecular clusters of silver in silicate nanoporous glasses has been developed. Composite materials containing molecular clusters of silver, silver nanoparticles and zinc oxide have been synthesized. The synthesis was carried out by impregnation of porous glasses in aqueous solutions of silver and zinc nitrates stabilized with high-molecular polyvinylpyrrolidone, followed by heat treatment of samples for decomposition of metal nitrates and polymer. Spectral-luminescent properties of composites have been investigated.

Silver/silver halide materials are considered as efficient and highly stable plasmonic photocatalysts for the organic pollutant degradation and hydrogen evolution from water splitting under solar irradiation, and they possess promising antibacterial activity. Ordered mesoporous silica materials including porous glasses are considered as the most promising template for silver-containing structures. In the present work, Ag/AgHal-doped (Hal = Cl, Br) vitreous membranes on a base of the mesoporous glasses were prepared via step-by-step single-stage impregnation procedure. The chemical and phase composition of the modified membranes were identified by the X-ray photoelectron spectroscopy, the X-ray diffraction and the energy-dispersive X-ray spectroscopy. The structure and morphology of inner membrane space were studied by the scanning electron microscopy. Electrokinetic properties of the silver-containing vitreous membranes were determined by the differential method and the streaming potential method. The inner membrane space is modified unevenly with appearance of the clearly defined regions with different silver content. The formation of the Ag/AgCl clusters along with the individual nanoparticles over thickness of the 1-mm membrane with mean pore radius of 23 nm was detected. The modification of the pore space by Ag-containing structures and the type of halogen ion almost do not affect the electrochemical behavior of the mesoporous vitreous membranes.

The spectral-optical and luminescence properties of bismuth-containing composite materials based on matrices of high-silica porous glasses are investigated. Luminescence spectra, luminescence excitation spectra, infrared transmission spectra (8000-4000 cm -1 ) depending on the composition of different types of matrices and sintering atmosphere (nitrogen, argon) of bismuth-containing composite materials were examined. It was found that the samples of bismuth-containing composite materials are characterized by UV (λ em =350 nm), blue-green (λ em =410-550 nm) and orange-red (λ em =600-725 nm) luminescence due to the presence of various bismuth active centers. The analysis of the spectra obtained by near-infrared spectroscopy demonstrates the formation of Bi 2+ dimers of bismuth and bismuth active centers associated with silicon. Keywords: Bismuth-containing composite materials, high-silica porous glass, near-infrared spectroscopy, luminescence, bismuth active centers.

Information about new cesium-containing quartzoid glasses (QGs) obtained as a result of the heat treatment of high-silica porous glasses (PGs) impregnated with aqueous solutions of CsNO 3 is presented. Quartzoid glasses have been studied by SEM, X-ray diffraction, flame photometry, and energy-dispersive X‑ray spectroscopy. It has been established that the total content of cesium in the synthesized QGs increases with an increase in the concentration of the impregnating solution of cesium nitrate and an increase in the impregnation time of PGs for the selected synthesis conditions.

Composite materials (CMs) based on matrices of high-silica nanoporous glasses activated by bismuth and yttrium ions have been synthesized. A study was made of the spectral-optical properties (transmission, optical density) and optical absorption characteristics (Urbach energy) of CMs depending on the ratio of introduced bismuth and yttrium (the mass ratio of nitrates in Bi/Y solution from 1 : 1 to 10 : 1) and CM heat-treatment temperature (from 50 to 870°С). Optical spectroscopy revealed that bismuth is in various forms in composites: spherical colloidal particles of bismuth, Bi 3+ , Bi 2+ , Bi + ions; Bi_5^3 + polycations, bismuth dimers. It has been established that the Urbach energy increases with an increase in the heat-treatment temperature of CMs. It was found that an increase in the content of yttrium in CMs (ceteris paribus) leads to the disappearance or appearance of additional absorption bands in the range of 395–740 nm associated with bismuth, which is in various forms (spherical colloidal particles of bismuth, Bi 3+ , Bi 2+ , Bi + ions; Bi_5^3 + polycations, bismuth dimers). In the composites, near-IR region spectroscopy was used to identify vibrations characteristic of lattice vibrations in Y 2 O 3 , to absorb Bi + ions, Bi 0 and bismuth dimers Bi_2^ + .

Composite materials (CMs) based on matrices of high-silica nanoporous glasses (NPGs) activated by bismuth and yttrium ions are synthesized. The CMs are studied by IR spectroscopy (1000–400 cm–1), depending on the Bi/Y nitrate ratio in the solution (1 : 1 and 10 : 1) and the heat treatment temperature of the CMs (from 470 to 870°C). The method of IR spectroscopy in composites identifies vibrations characteristic of the cubic modification Y2O3 and for the monoclinic modification of bismuth oxide (α–Bi2O3); for vibrations of Bi–O and Bi–O–Bi bonds, as well as Bi3+ cations in [BiO6] and/or [Bio3] structural units; and for vibrations of Bi–O–Si bonds, and for Y–O–Y and Y–O bonds. It is established that an increase in the yttrium content in CMs heat-treated at 470 and 870°C, (all other things being equal) leads to the appearance of additional absorption bands at 564, 556, 432, and 424 cm–1, which may be related to the formation of the cubic phase Y2O3.

High-silica mesoporous (pore radii 1.5–1.6 nm, MIP and pore radii 18.4–25.2 nm, MAP) vitreous AgI-doped membranes of the Vycor type have been manufactured. Characterization of the mesoporous glass morphology carried out by scanning electron microscopy (SEM). Successful synthesis of AgI-doped mesoporous glasses was confirmed by X-ray fluorescence (XRF) spectroscopy and energy-dispersive X-ray (EDX) spectroscopy. For the first time a comprehensive study of structural characteristics and electrokinetic properties (surface conductivity, streaming potential) of the AgI-doped MIP and MAP glasses in NaNO 3 , KNO 3 and AgNO 3 solutions in the concentration range 0.1–0.0001 M have been performed. The electrokinetic potential (ζ-potential) was found by the streaming potential method taking into account the surface conductivity and the electric double layers (EDL) overlap. The results were compared with the ζ-potential calculated from the electrophoretic mobility of the particles (laser Doppler velocimetry). It has been established that the structure of EDL in membrane nanopores and on the open surface of the AgI-doped porous particle differ significantly—different signs of the streaming potentials (negative) and electrophoretic mobility (positive) were observed for the AgI-doped glasses in AgNO 3 solution.

Composite materials (CMs) activated by silver and lanthanum ions based on high-silica porous glass (PG) matrices have been synthesized. The CMs were studied by IR spectroscopy in the narrow frequency range of 1000–400 cm–1 at room temperature. The bands corresponding to the Ag–O, Ag–O–Ag, O–Ag–O, La–O–H, and La–O bonds vibrations were detected on the infrared transmission spectra of the CMs. In addition, bands corresponding to the presence of Ag2O, La2O3 were found. Accordingly the energy-dispersive X-ray spectroscopy method the lanthanum and silver are evenly distributed throughout the thickness of the samples.