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The NanoPES photoelectron beamline installed at the Kurchatov Synchrotron Radiation Source is presented. The beamline uses bending magnet radiation of the Sibirea-2 storage ring, and includes grazing incidence monochromator with plane gratings for photon energy range of 25–1500 eV as well as the experimental station designed for investigations using photoelectron spectroscopy and absorption spectroscopy techniques. Capabilities of the experimental station are expanded by electron spectroscopy for chemical analysis and probe microscopy modules.

The samples of Ni-doped bismuth magnesium tantalate pyrochlores with the general formula Bi1.4(Mg1-x Ni x )0.7Ta1.4O6.3 (x = 0.3, 0.5, 0.7) were obtained by solid-phase synthesis. The crystal structure of the pyrochlore type (sp. gr. Fd3m:2) was clarified by the Rietveld method on the basis of X-ray powder diffraction data. The unit cell parameters increase with the decreasing nickel content in the range from 10.5319(1) to 10.5391(1) A. The electronic state of atoms is established by the XPS method. According to XPS analysis, bismuth atoms have an effective charge of +3, nickel atoms +(2 + δ), and tantalum ions +(5 - δ). The coefficient of thermal expansion of the lattice of the samples was calculated from high-temperature X-ray structural measurements in the range of -180 to 1050 °C. The average values of linear TECs α in the temperature ranges of 30-570 and 600-1050 °C are 5.1 × 10-6 and 8.1 × 10-6 °C-1, respectively. The monotonicity of the change in the thermal expansion coefficient in the temperature range from -100 to 1050 °C indicates the absence of phase transformations. All samples are dielectric and exhibit high activation energies ∼2.0 eV, moderately high dielectric constants ∼24-28, and tangent dielectric losses ∼0.002 at 1 MHz and 21 °C. The electrical properties of the samples are described by a simple parallel equivalent scheme. The chemical composition of the materials has little effect on the polarizability of the medium or on the value of the activation energy of the conductivity. Ionic processes in investigated materials at frequencies 200-106 Hz and at temperatures 100-450 °C were not detected.

We report on a comparative study of the performance level of H2/O2 PEM fuel cells in which the catalytic layers containing Pt nanoparticles were deposited on the microporous layer side of gas diffusion electrodes, using three different deposition techniques: (i) by magnetron sputtering, (ii) by impregnation followed by chemical reduction (using either ethylene glycol or hydrogen or sodium borohydride as reducing agent), and (iii) by spraying a catalytic ink (containing either Pt/C or bulk Pt particles). The microstructure and chemical composition of the different catalytic layers has been determined by SEM, TEM, XRD and XPS analysis. Their electrochemical surface areas have been determined by cyclic voltammetry. The i-V curves have been measured and compared. A durability stress test based on cycles of potential was used to assess the degradation rate of the different catalytic layers and to rank performance.

New NT:M/zeolite composites with functional nanoparticles of titanium(IV) oxides NT (η-phase and anatase) have been prepared by introducing nitrates with dopant metals (M = Ag, Ni, and V) and zeolites (H-Beta and H-ZSM-5) within the process of NT synthesis during the hydrolysis of TiOSO4·nH2O. The prepared composites have been characterized by X-ray diffraction, XAS-method, XPS-spectroscopy, UV-Vis diffuse reflectance spectroscopy, and Brunauer–Emmett–Teller and chemoluminescence methods. The greatest photodegradation rate constants (visible light radiation) were achieved in the reaction of thiamethoxam pesticide and difenoconazole fungicide oxidation in the presence of NE:Ni/H-Beta (NE – η-phase with composition TiO2−x·nH2O), i.e. k = 0.0270 min−1 and k = 0.0147 min−1 respectively, that is 2.5 times higher than the k value obtained for the commercial anatase Hombifine N (UV-irradiation). A relationship between the photocatalytic activity (PCA) and the NT:zeolite ratio, the type and concentration of M, the type of NT and zeolite, the content of OH groups and the reactive oxygen species (radical anions ˙OH, ˙O2− and H2O2) on the surface, and the composition and structure of the decomposed pollutant has been found. The decisive role of the composition of the volume and surface of nanocomposites in the realization of PCA has been noted. The adsorption (removal of P(V), As(V), Se(VI) ions from aqueous solutions) and antimicrobial activities (against bacteria Staphylococcus epidermidis, Bacillus antracoides, Escherichia coli) of the NT:M/zeolite composites, in the absence of light emission, have been studied for the first time and their high performance has been demonstrated: the removal degrees of P(V), As(V), and Se(VI) ions from aqueous solutions in the presence of all composites were more than 99% and the inhibition growth zone of composites NA:Ag/zeolite was >13 mm. New composites could be recommended for preparing wound dressings, antiseptic ointments for external use and water filters.

Carbon nanomaterials doped with heteroatoms, in particular, nitrogen atoms, are of great interest for electrochemical power engineering as nonmetallic catalysts or carriers of catalytically active metal nanoparticles. A nanostructured, reduced graphene oxide modified with nitrogen in a gas discharge plasma in a vacuum chamber of a magnetron-ion sputtering facility is considered. It is shown that plasma treatment of reduced graphene oxide does not cause undesirable morphological changes in the structure of carbon nanomaterial, but it leads to the incorporation of nitrogen atoms into the structure of reduced graphene oxide with the formation of pyridine-, pyrrole-, and graphite-like configurations. The application of pulsed negative bias voltages of various magnitudes to the substrate with the sample increases the concentration of nitrogen atoms to 2.6 at % and also promotes an increase in the proportion of nitrogen atoms in the pyridine form and a slight decrease in the proportion of atoms in the pyrrole form. The results allow for considering the obtained carbon nanomaterials for use as components of electrochemical devices, for example, fuel cells, in the future.

Composite nanoparticles with a core consisting of associated anatase crystallites and a polymeric shell consisting of poly(N-vinylpyrrolidone) or poly(N-vinylcaprolactam) were synthesized and found to have antimicrobial activity against Escherichia coli and Staphylococcus aureus as well as photocatalytic activity in decomposition of methyl orange and methylene blue dyes. The highest antibacterial activity of the particles with poly(N-vinylpyrrolidone) shell is due to the larger amount of S O 4 2 − groups and water adsorbed on the surface, while their photocatalytic activity is comparable with that of commercial nanoanatase samples.

The structural features and current–voltage curves of metal/nanocomposite/metal sandwiches based on (Co40Fe40B20)x(LiNbO3)100 –x nanocomposites synthesized on SiO2/Si substrates were studied. Samples were fabricated by ion-beam sputtering of a composite target, which provided an opportunity to produce nanocomposites with different compositions x = 5–48 at % in a single cycle. The results of electron microscopy analysis revealed that the obtained nanocomposites consisted of metallic granules in an amorphous nonstoichiometric matrix. These granules were ~2–3 nm in size and had a near-spherical (slightly elongated along the growth direction) shape. The local chemical composition of nanocomposite films was examined using X-ray photoelectron spectroscopy. The structures demonstrated resistive switching with the highest ratio of resistances in the low- and high-resistance states (~10) achieved at x ~ 13 at %. The number of write/erase cycles exceeded 104. The observed effect of resistive switching is attributable to the influence of oxygen vacancies on the tunneling conductivity of contacts of percolation granule chains with one of the electrodes of the structure, which is separated by a highly oxidized layer from the nanocomposite.

Hydrolysis of TiOSO4 · xH2SO4 · yH2O and TiOSO4 · xH2O, performed in the presence of poly-N-vinylcaprolactam (PVCL) or poly-N-vinylpyrrolidone (PVP) and in an aqueous medium, has provided for the first time samples containing nanophases of, respectively, η-modification of TiO2 – x · nH2O ( intercalates TiO2 – x · (nH2O, PVCL) or TiO2 – x · (nH2O, PVP)) and with anatase structure (TiO2). The samples have been characterized by X-ray diffraction and X-ray photoelectron spectroscopy. They are found to have different antimicrobial activities. A relationship is established between the antimicrobial activity and the structural features of titanium(IV) oxide; concentration of hydrated titanium dioxide in the samples; and the content of free water and hydroxyl and $${\text{SO}}_{4}^{{2 - }}$$ groups on the surface of anatase and η-phase nanoparticles, respectively. The choice of polymer does not affect the antimicrobial activity.

The paper is devoted to the study of the adsorption of C60F18 fullerene fluoride molecules with high dipole moment on a graphene-like surface in order to investigate the possibility of creating interfaces with given physical and chemical characteristics and controlling their properties. Using atomic force microscopy, X-ray photoelectron spectroscopy, and quantum chemical calculations, the island structure of thin films of C60F18 polar molecules on the surface of highly oriented pyrolytic graphite has been first found. The chemical stability of fluorinated fullerene molecules in the adsorbed film and the island growth of the film according to the Volmer–Weber mechanism up to large degrees of coverage have been established. The nature of the interaction between adsorbate molecules and the substrate has been determined. The influence of collective electrostatic effects on the structure of the monolayer, the total energy of the system, and the shift of the core electronic levels have been concluded.

Stable colloids of hard magnetic particles are newly developed and very promising materials. Surface functionalization of these particles remains challenging because the particles tend to aggregate during reaction due to strong magnetic interactions. Herein we report on a synthesis of strontium hexaferrite hard magnetic nanoparticles coated with silica by hydrolysis of tetraethoxysilane. As a source of hexaferrite we used stable colloid of plate-like nanoparticles with mean diameter of 40 nm and thickness of 5 nm, which were prepared by a glass-ceramic process. We have shown that to successfully coat each hexaferrite particle individually the hydrolysis conditions should provide heterogeneous nucleation of silica with rate higher than the aggregation rate of the colloidal nanoparticles. The resulting materials represent single crystal hexaferrite cores wrapped in silica shell with mean thickness of 18 and 23 nm depending on synthesis conditions. The obtained core-shell particles can be easily dispersed as stable aqueous colloids. The materials can be used as magnetic sorbents or nanocontainers and, furthermore, they are very promising colloidal building blocks for various magnetically assembled nanostructures.

The anatase nanoparticles are stabilized with titanium tetraisopropoxide Ti[OCH(CH3)2]4 and isopropyl alcohol without surfactants suitable for biological studies. We showed that the hydrodynamic radii in suspensions depend on temperature and the duration of hydrolysis, whereas the composition (a mixture of anatase with brookite, anatase, brookite, and rutile) and the sizes of crystallites (X-ray), nanoparticles, and aggregates (SEM) in the dried state are mainly dependent on the pH of the environment. The nonphase of the samples stems from coherent intergrowth of unit cells of anatase and brookite via geometric and structural complementarity. We found that photocatalytic activity (PCA; Rhodamine 6G model dye under UV radiation) depends on OH/H2O ratio (adsorbed), whereas antimicrobial activity (AMA) in the dark depends on an amount of free water on the surface of nanoparticles according to X-ray photoelectron spectroscopy (XPS). We revealed that samples with the smallest sizes of nanoparticles of all levels possess the highest PCA and AMA relative to Staphylococcus aureus and Escherichia coli.

Platinum (Pt)-based electrocatalysts supported by reduced graphene oxide (RGO) were synthesized using two different methods, namely: (i) a conventional two-step polyol process using RGO as the substrate, and (ii) a modified polyol process implicating the simultaneous reduction of a Pt nanoparticle precursor and graphene oxide (GO). The structure, morphology, and electrochemical performances of the obtained Pt/RGO catalysts were studied and compared with a reference Pt/carbon black Vulcan XC-72 (C) sample. It was shown that the Pt/RGO obtained by the optimized simultaneous reduction process had higher Pt utilization and electrochemically active surface area (EASA) values, and a better performance stability. The use of this catalyst at the cathode of a proton exchange membrane fuel cell (PEMFC) led to an increase in its maximum power density of up to 17%, and significantly enhanced its performance especially at high current densities. It is possible to conclude that the optimized synthesis procedure allows for a more uniform distribution of the Pt nanoparticles and ensures better binding of the particles to the surface of the support. The advantages of Pt/RGO synthesized in this way over conventional Pt/C are the high electrical conductivity and specific surface area provided by RGO, as well as a reduction in the percolation limit of the components of the electrocatalytic layer due to the high aspect ratio of RGO.

This conference contribution is focused on decoration of WS2 nanotubes (NT-WS2) with gold and silver nanoparticles via facile routes implying direct reaction of tungsten disulfide with water-soluble AuIII and AgI species at 100°C. The underlying mechanism of these interactions will be discussed in details based on extensive studies of reaction mixtures and resulting metal–NT-WS2 nanocomposites, including thorough X-ray photoelectron spectroscopy (XPS) analysis. Surprising features in optical spectra of the designed nanocomposites would be reported, including suppression of plasmon resonance in tiny noble metal nanoparticles (< 10 nm in diameter) grown onto NT-WS2. The plasmonic features of individual gold nanoparticles on the surface of disulfide nanotube were also characterized by electron energy loss spectroscopy in scanning transmission electron microscopy mode (STEM-EELS). Photoresistive NO2−sensing response of NT-WS2 under green light illumination (λmax = 530 nm) and its enhancement by plasmonic gold “nanoantennas” will be reported as well.

Titanium oxide(IV)/zeolite nanocomposites obtained through the introduction of Beta(25), ZSM-5(12), MOR(5), and Y(2) zeolites into the reaction mixture, during the hydrolysis of titanyl sulphate, exhibit greater photocatalytic activity in the photodegradation reactions of methyl orange under ultraviolet radiation and a higher adsorption capacity to extract P(V) and As(V) from model aqueous environments compared to zeolites and nanoscale anatase prepared in the same way. The increase in the functional properties of nanocomposites is due to a higher amount of OH groups (photocatalytic activity and adsorption capacity) and lower amount of H2O (photocatalytic activity) on their surface, which is revealed with X-ray photoelectron spectroscopy. Moreover, spherical shape of particles with smaller average sizes than those of zeolites, which are characterized by a more diverse morphology, increases the photocatalytic activity and adsorption capacity of the nanocomposites.

Composites of WS2 nanotubes (NT-WS2 ) and gold nanoparticles (AuNPs) were prepared using aqueous HAuCl4 solutions and subjected to surface analysis. The obtained materials were jointly characterized by X-ray photoelectron (XPS), Raman scattering (RSS), and ultraviolet photoelectron (UPS) spectroscopies. Optical extinction spectroscopy and electron energy loss spectroscopy in the scanning transmission electron microscopy regime (STEM-EELS) were also employed to study plasmon features of the nanocomposite. It was found that AuNPs deposition is accompanied by a partial oxidative dissolution of WS2 , whereas Au-S interfacial species could be responsible for the tight contact of metal nanoparticles and the disulfide. A remarkable sensitivity of n-type resistance of NT-WS2 and Au-NT-WS2 to the adsorption of NO2 gas was also demonstrated at room temperature using periodical illumination by a 530 nm light-emitting diode. Au-NT-WS2 nanocomposites are found to possess a higher photoresponse and enhanced sensitivity in the 0.25-2.0 ppm range of NO2 concentration, as compared to the pristine NT-WS2 . This behaviour is discussed within the physisorption-charge transfer model to explore sensing properties of the nanocomposites.

PVCL-intercalated samples containing nano-dimensional phases with η-modification of the TiO2−x·nH2O composition are obtained by hydrolysis of TiOSO4·xH2SO4·yH2O or TiOSO4·xH2O in the presence of poly(N-vinylcaprolactam) (PVCL). The incorporation of PVCL with water molecules into the interlayer space of the structure of the η-phase—TiO2−x·(PVCL nH2O)—is established by the X-ray diffraction study while the presence of PVCL in the sample composition is confirmed by the X-ray photoelectron and IR spectroscopy CHNS analysis and X-ray spectral microanalysis. Intercalated samples manifest the antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans. It is shown that the sample composition (the content of hydrated titanium dioxide) the composition of the η-phase (the presence of PVCL and H2O or the water content in the interlayer space of the structure), and the surface composition (S in the form of SO42− groups O in the form of adsorbed water and OH groups) affect the antimicrobial activity in the dark.

For adequate description of the adsorption and self-assembly of C60F18 polar molecules on the surface Au(111), quantum-chemical studies of the electronic and electrical properties of a single molecule are performed. Using various procedures of density functional theory, the electric dipole moment of the molecule, distributions of the electrostatic potential, electric-field magnitude and electron density are calculated with controlled accuracy for the first time. An improved value of the electric dipole moment of the C60F18 molecule is obtained in a range from 10 to 11 D. The known approximation of a point dipole for electric-field strength is shown to be fulfilled within an accuracy of 30% even at distances twice greater than the size of the molecule. The structural fragments of the calculated lowest unoccupied and highest occupied molecular orbitals are assigned to their images, which were previously obtained using scanning tunneling microscopy and spectroscopy.

Titania nanoparticles (anatase or anatase + rutile) with enhanced photocatalytic activity were successfully produced by treating titanyl sulfate with various peroxo compounds (hydrogen peroxide, ammonium persulfate, and urea hydrogen peroxide) with further annealing. Transformation of titanyl sulfate to titanium dioxide was investigated by X-ray diffraction, electron microscopy, X-ray microanalysis, IR, Raman, X-ray photoelectron, and UV/vis spectroscopy. The peroxo compound and annealing temperature play an important role in phase composition and properties of the samples. Correlations between phase composition, oxygen content, band gaps, and constant rates for methyl orange (MO) discoloration were found. The [TiOx(O2)2−x(H2O)m] phase, which forms on the first stage of the reaction, contains nanoparticles with small crystallites (1–2 nm) and promotes formation of titanium dioxide with the anatase structure. Thermal decomposition of the peroxo-containing phase results in formation of titanium dioxide. Oxygen excess prevents transformation of anatase to rutile, decreases band gap, and increases activity of titanium dioxide (anatase or anatase + rutile) in the model reaction of MO destruction.

Samples containing vanadium-doped nanosized titanium(IV) oxides with anatase and η-phase structures were prepared by a modified sulfate process, and samples with vanadium-doped η-phase were prepared for the first time. The bulk and the surface of the samples were characterized by a lot of methods, including X-ray diffraction, diffuse reflectance spectroscopy, X-ray absorption spectroscopy (EXAFS/XANES), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). The photocatalytic activity (PCA) of the samples was studied in the reaction of photodegradation of the cationic dye rhodamine 6G (in the visible region) and the systemic triazole fungicide difenoconazole (in the UV and visible regions). The PCA was found to be influenced by the phase composition of the samples, the composition of their surface, and nanosized titanium(IV) oxide modifications. Vanadium-doped samples with η-phase containing different ions (Ti3+, Ti4+, V4+, and V5+) and reactive OH groups on the nanoparticle surface exhibited the highest PCA. The samples were shown to have a higher adsorption capacity (AC) for the extraction of As(V) (the highest AC in the presence of vanadium-doped anatase and η-phase) and P(V) (the highest AC in the presence of undoped anatase and η-phase) anions from aqueous systems. The adsorption capacity correlates with the amount of reactive OH groups on the nanoparticle surface and does not depend on the modification of the adsorbent. Only vanadium-doped anatase containing the largest fraction of an amorphous component and the largest amount of SO42− groups on its nanoparticle surface exhibits antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Bacillus anthracoides. Vanadium doped anatase and η-phase can be used to purify aquatic environments of harmful organic pollutants and a wide range of anions.

The current work is dedicated to investigation of the interaction between self-assembled polar molecules of fullerene fluoride C60F18 with the chemically active surface Ni(100) under radiation and heat treatments. X-ray photoelectron spectroscopy is used in combination with quantum-chemical simulation. For the first time, the transformation of an as-deposited dielectric continuous 2D thin film to a 3D island-type assembly with molecular ordering within the islands is shown to take place. The degree of coverage of the Ni surface by C60F18 islands (0.6–0.7) and their height (~6 nm) are estimated. Quantum-chemical simulation shows that the chemisorption energy of the C60F18 molecule on the Ni surface equals ~6.6 eV and fluorine atoms are located at a distance of 1.9 A above the Ni surface. The results of the investigation provide an opportunity to create nanoscale ordered structures with local changes in the work function.

The combined X-ray absorption and emission spectroscopy approach was applied for the detailed electronic structure and composition studies of silicon nanoparticles produced by the ultrasound milling of heavily and lowly doped Si nanowires formed by metal-assisted wet chemical etching. The ultrasoft X-ray emission spectroscopy and synchrotron based X-ray absorption near edges structure spectroscopy techniques were utilize to study the valence and conduction bands electronic structure together with developed surface phase composition qualitative analysis. Our achieved results based on the implemented surface sensitive techniques strongly suggest that nanoparticles under studies show a significant presence of the silicon suboxides depending on the pre-nature of initial Si wafers. The controlled variation of the Si nanoparticles surface composition and electronic structure, including band gap engineering, can open a new prospective for a wide range Si-based nanostructures application including the integration of such structures with organic or biological systems.

Scientific reports 10(1), 6902 (2020). doi:10.1038/s41598-020-63935-3, In this paper we present a facile method for the synthesis of aminated graphene derivative through simultaneous reduction and amination of graphene oxide via two-step liquid phase treatment with hydrobromic acid and ammonia solution in mild conditions. The amination degree of the obtained aminated reduced graphene oxide is of about 4 at.%, whereas C/O ratio is up to 8.8 as determined by means of X-ray photoelectron spectroscopy. The chemical reactivity of the introduced amine groups is further verified by successful test covalent bonding of the obtained aminated graphene with 3-Chlorobenzoyl chloride. The morphological features and electronic properties, namely conductivity, valence band structure and work function are studied as well, illustrating the influence of amine groups on graphene structure and physical properties. Particularly, the increase of the electrical conductivity, reduction of the work function value and tendency to form wrinkled and corrugated graphene layers are observed in the aminated graphene derivative compared to the pristine reduced graphene oxide. As obtained aminated graphene could be used for photovoltaic, biosensing and catalysis application as well as a starting material for further chemical modifications., Published by Macmillan Publishers Limited, part of Springer Nature, [London]

In this paper, we for the first time demonstrate efficient nitrogen doping of graphene oxide (GO) with nitrogen concentration of up to 5 at.% via modified Hummers' method. Using X-ray photoelectron spectroscopy (XPS), X-ray absorbance spectroscopy (XAS) and Fourier transform infrared spectroscopy (FTIR) techniques, we have found out graphitic nitrogen to be the dominant type of the implemented nitrogen species. At the same time, the subsequent GO thermal reduction to graphene appears to result in a transformation of the graphitic nitrogen into pyridines and pyrroles. The mechanisms of the observed GO nitrogen doping and conversion of the nitrogen species are proposed, providing an opportunity to control the type and concentration of the implemented nitrogen within the approach. A two-time increase of the graphenes' conductivity is observed due to the performed nitrogen doping. Further comprehensive electrical studies combined with the transmission electron microscopy (TEM) and density functional theory (DFT) modeling have allowed us to estimate the conductivity mechanism and the impact of the implemented nitrogen. As a net result, a simple method to synthesize N-doped graphene with the desired type of the nitrogen species is developed, which leads to new perspective applications for graphene, i.e. supercapacitors, catalysis, and sensors.

Pt/C and Pt/SnOx/C catalysts were synthesized using the polyol method. Their structure, morphology and chemical composition were studied using a scanning electron microscope equipped with an energy dispersive X-ray spectrometer, transition electron microscope and X-ray photoelectron spectroscope. Electrochemical measurements were based on the results of rotating disk electrode (RDE) experiments applied to ethanol electrooxidation. The quick evaluation of catalyst activity, electrochemical behavior, and an average number of transferred electrons were made using the RDE technique. The usage of SnOx (through the carbon support modification) in a binary system together with Pt causes a significant increase of the catalyst activity in ethanol oxidation reaction and the utilization of ethanol.

European Conference on Surface Science (ECOSS), Antalya, TURKEY, AUG 31-SEP 05, 2014; Scanning tunneling microscopy and spectroscopy studies of C60F18 molecules deposited on Au(111) are reported and compared to C-60 molecules both at liquid helium temperature and room temperature (RT). Whereas adsorption and electronic properties of C60F18 single molecules were studied at low temperature (LT), self-assemblies were investigated at RT. In both cases, the fluorine atoms of the C60F18 molecules are pointed towards the surface. Individual C60F18 molecules on Au(111) have a HOMO-LUMO gap of 2.9 eV. The self-assembled islands exhibit a close-packed hexagonal lattice with amorphous borders. The comparison with C-60 molecules clearly demonstrates the influence of the C60F15 electric dipole moment (EDM) on the electronic properties of single molecules and on the thermodynamics of self-assembled islands. Besides, the apparent height value of a separate molecule increases in a self-assembly environment as a result of a depolarization phenomenon. (C) 2015 Elsevier B.V. All rights reserved.

A detailed study of the structure, morphology and electrochemical properties of Pt/C and Pt/x-SnO2/C catalysts synthesized using a polyol method has been provided. A series of catalysts supported on the SnO2-modified carbon was synthesized and studied by various methods including transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electrochemical methods, and fuel cell testing. The SnO2 content varies from 5 to 40 wt %. The TEM images, XRD and XPS analysis suggested the Pt-SnO2 hetero-clusters formation. The SnO2 content of ca. 10% ensures an optimal catalytic layer structure and morphology providing uniform distribution of Pt-SnO2 clusters over the carbon support surface. Pt/10wt %-SnO2/C catalyst demonstrates increased activity and durability toward the oxygen reduction reaction (ORR) in course of accelerated stress testing due to the high stability of SnO2 and its interaction with Pt. The polymer electrolyte membrane fuel cell current&ndash, voltage performance of the Pt/10wt %-SnO2/C is comparable with those of Pt/C, however, higher durability is expected.

Angular dependences of the fine structure of near-edge X-ray absorption (NEXAFS) of carbon C1s spectra are obtained for a monolayer film of C60F18 polar molecules on a Ni (100) substrate. The fine structure and angular dependences of these spectra are interpreted using calculation data obtained by the density functional method upon fitting NEXAFS spectra by the set of trial functions. It is shown that during deposition, the dipole moment of molecules is oriented perpendicular to the surface and fluorine atoms are the ones closest to the surface.

The angular dependence of near edge X-ray absorption fine structure (NEXAFS) spectra has been obtained in the vicinity of carbon and fluorine 1s absorption edges in a monolayer film of polar fullerene fluoride (C60F18) molecules on a Ni(100) substrate. The fine structure of the spectra has been identified according to experimental data via calculations based on the density functional theory, and the angular dependence of the spectra has been explained. The orientations of structural molecular fragments are determined from the angular dependence of the NEXAFS spectra. It is demonstrated that the electric dipole moment of a C60F18 molecule is oriented along the normal to the substrate surface with an accuracy of 5°.