Mikhail A Soldatov

Southern Federal University | sfedu · Research Center for Nanoscale Structure of Matter

Fine tuning of the material properties requires many trials and errors during the synthesis. The metal nanoparticles undergo several stages of reduction, clustering, coalescence and growth upon their formation. Resulting properties of the colloidal solution thus depend on the concentrations of the reagents, external temperature, synthesis protocol...

One-dimensional magnetic nanomaterials, such as nano-rods, are one of the most interesting but unexplored objects due to the complexity of their manufacture. In this work, we report on the template-assisted preparation of rod-shaped cobalt ferrite (CoFe 2 O 4) nanoparticles (NPs) using the akaganeite (β-FeOOH) matrix and their application as multif...

Novel proton-conducting hybrid membranes consisting of sulfonated multiblock copolymer of polysulfone and polyphenylsulfone (SPES) reinforced with a HKUST-1 metal-organic framework (MOF) (5, 10, and 20 wt. %) were prepared and characterized for fuel cell applications. The presence of the MOF in the copolymer was confirmed by means of FE-SEM and EDS...

The structure and properties of nanoparticles are greatly influenced by the synthesis method and the stabilizer used in their preparation. The paper presents the results of the effect of various stabilizers (gelatin, sodium citrate, sodium borohydride) on the structure, synthesis, and tribotechnical properties of silver nanoparticles. The mechanism...

We report herein a Pt(IV) prodrug with metronidazole in axial positions Pt-Mnz. The nitroaromatic axial ligand was conjugated with a cisplatin scaffold to irreversibly reduce under hypoxic conditions, thereby retaining the Pt(IV) prodrug in the area of hypoxia. X-ray near-edge adsorption spectroscopy (XANES) on dried drug-preincubated tumor cell sa...

We report a new one-step room-temperature electrochemical synthesis of γ-Fe2O3@MIL-88a magnetic composite. Anode from metallic iron was used as Fe-source. We did not use any toxic or hazardous solvents. A careful, comprehensive characterization of the obtained material was applied, including a synchrotron experiment. The γ-Fe2O3@MIL-88a composite c...

Beneficial features of biocompatible high-capacity UiO-66 nanoparticles, mesoporous SiO2, and folate-conjugated pluronic F127 were combined to prepare the core-shell UiO-66@SiO2/F127-FA drug delivery carrier for targeted cellular uptake in cancer treatment. UiO-66 and UiO-66-NH2 nanoparticles with a narrow size and shape distribution were used to f...

The attempts to develop efficient methods of solar energy conversion into chemical fuel are ongoing amid climate changes associated with global warming. Photo-electrocatalytic (PEC) water splitting and CO2 reduction reactions show high potential to tackle this challenge. However, the development of economically feasible solutions of PEC solar energ...

Low-toxic colloidal superparamagnetic iron oxide nanoparticles (SPIONs) for theranostic applications were obtained by microwave-assisted technique. Nanoparticles were synthesized by the hydrothermal method under different conditions. XANES, XRD, and XPS studies support the maghemite (γ-Fe2O3) atomic and electronic structure of the nanoparticles. XA...

Naturally inspired biomaterials such as calcium carbonate, produced in biological systems under specific conditions, exhibit superior properties that are difficult to reproduce in a laboratory. The emergence of microfluidic technologies provides an effective approach for the synthesis of such materials, which increases the interest of researchers i...

A description is given of a facility to study optical response of X-ray luminophores considered as a component of composite materials for X-ray photodynamic therapy. The concept and basic principles of X-ray photodynamic therapy are presented. Test results of the developed facility are presented, methods of optimizing the signal/noise ratio by vary...

X-ray photodynamic therapy (XPDT) has been recently considered as an efficient alternative to conventional radiotherapy of malignant tissues. Nanocomposites for XPDT typically consist of two components—a nanophosphor which re-emits X-rays into visible light that in turn is absorbed by the second component, a photosensitizer, for further generation...

It is known that the initiation of photodynamic therapy (PDT) in deep-seated tumors requires the use of X-rays to activate the reactive oxygen species generation in deep tissues. The aim of this paper is to synthesize X-ray nanophosphors and analyze their structural and luminescence characteristics to push the PDT process deep into the body. The ar...

The aim of the present work was to investigate the toxic effects of zinc oxide nanoparticles (ZnO NPs, particle size < 50 nm) on the physiological and anatomical indices of spring barley (Hordeum sativum L.). The results show that ZnO NPs inhibited H. sativum growth by affecting the chlorophyll fluorescence emissions and causing deformations of the...

X-ray Fluorescence Measurements, Table S1: Net element concentration, wt.%±one sigma error, Table S2: Atom element concentration, at. %; Figure S1: Optical microscopyimage of the measured area and XRF spectra for the control sample, Figure S2: Optical microscopyimage (top) of the measured area and XRF spectra (bottom) for the 300 mg/L ZnO NPs sampl...

The first representative of a new class of charge transfer complexes for organic semiconductors was synthesized. The reaction of p-nitroaniline (PNA) with [1,10]-phenanthroline-5,6-dione (PD) results in the formation of a stable molecular charge transfer (CT) complex PNA3-PD2 in a ratio of 3:2. The structure of the molecular CT complex PNA3-PD2 was...

Nowadays, an important area of research in the field of two-dimensional (2D) materials and their surface characteristics is acceleration of the process of searching for synthesis parameters for new structures with unique properties. The achieved level of development of artificial intelligence and especially machine learning makes it possible to use...

Two metal-organic frameworks (MOFs), UiO-66 and UiO-66-NH2, were considered as containers for bioactive chemicals. We provide a synthesis technique, which allowed the production of these materials suitable for biomedical applications. Both MOFs were characterized as single-phase porous materials composed of nanoparticles (30-65 nm) with a ζ-potenti...

Zinc based nanoparticles (NPs) have a great importance among the metal-based NPs and widely produced after SiO2 and TiO2. The rapid growth of ZnO NPs production and its abundant uses in many industries, and increasing release into an environment from both intentional and unintentional sources, create risks to human health. The recent finding of ZnO...

Innovations often play an essential role in the acceleration of the new functional materials discovery. The success and applicability of the synthesis results with new chemical compounds and materials largely depend on the previous experience of the researcher himself and the modernity of the equipment used in the laboratory. Artificial intelligenc...

Micro - X-ray Absorption Near Edge Structure (μXANES) at the Fe K-edge of biological tissues after admission of superparamagnetic iron oxide nanoparticles (SPIONs) has been used to monitor the iron oxidation state in the nanoparticles and in the native tissues. It was found that μXANES technique with submicron spatial resolution is sensitive enough...

Synthesis of the MIL-100 metal-organic framework particles was carried out by hydrothermal (HT) and microwave (MW)-assisted methods. Transmission electron microscopy showed formation of microparticles in the course of hydrothermal synthesis and nanoparticles for microwave-assisted synthesis. Powder X-ray diffraction confirmed formation of larger cr...

A series of 73 ligands and 73 of their Cu+2 and Cu+1 copper complexes with different geometries, oxidation states of the metal, and redox activities were synthesized and characterized. The aim of the study was to establish the structure-activity relationship within a series of analogues with different substituents at the N(3) position, which govern...

: We report here a simple two-stage synthesis of zinc–cobalt oxide nanoparticles. We used Zn/Co-zeolite imidazolate framework (ZIF)-8 materials as precursors for annealing and optional impregnation with a silicon source for the formation of a protective layer on the surface of oxide nanoparticles. Using bimetallic ZIFs allowed us to trace the phase...

The increased application and releases of nanoparticles in the environments have drawn consideration of scientific attention. The potential release of nanoparticles could increase concentration in the atmosphere which may impact on plants and other biota of soil systems. The present chapter focused on fate and toxicity of metallic nanoparticles on...

X-ray absorption near-edge spectroscopy (XANES) is becoming an extremely popular tool for material science thanks to the development of new synchrotron radiation light sources. It provides information about charge state and local geometry around atoms of interest in operando and extreme conditions. However, in contrast to X-ray diffraction, a quant...

We report two successful synthesis techniques resulted in single-phase Zn-ZIF-65 with a high specific surface area. The solvothermal method allowed to obtain large well-shaped crystals used for single-crystal XRD. We report a new MW assisted technique, which leads to a fast formation of ZIF-65 with hierarchical pore system; obtained samples contain...

In the past two decades, increased production and usage of metallic nanoparticles (NPs) have inevitably increased their discharge into the different compartments of the environment, which ultimately paved the way for their uptake and accumulation in various trophic levels of the food chain. Due to these issues, several questions have been raised on...

In this work we have applied machine learning methods (Extra Trees, Ridge Regression and Neural Networks) to predict structural parameters of the system based on its XANES spectrum. We used two ML approaches: direct one, i.e. when ML model is trained to predict the structural parameters directly from the XANES spectrum and inverse one when ML model...

The good wear-resistance of state-of-the-art liquid lubricants is due to the formation of complex metal and organometallic films onto the friction surface, reducing the friction and wear. For this purpose, various additives of metal nanopowders are used, especially ones based on copper. The formation and growth of Cu nanoparticles, as well as the t...

Ab initio simulations of the pre-edge XAS spectra and other related resonance spectroscopies require taking into account 3d-4p hybridization on the 3d metal site. While the hybridization Hamiltonian could be parameterized on the basis of the symmetry of the system we introduce instead a set of 4p orbitals directly within the local Hamiltonian of th...

In the last decade the appearance of progressively more sophisticated codes, together with the increased computational capabilities, has made XANES a spectroscopic technique able to quantitatively confirm (or discard) a structural model, thus becoming a new fundamental diagnostic tool in catalysis, where the active species are often diluted metal c...

Large iron oxide nanoparticles are studied by high-energy resolution fluorescence-detected X-ray absorption spectroscopy (HERFD XANES). A theoretical procedure within the finite-difference method framework is tested to calculate Fe K-edge X-ray absorption spectra for the magnetite structure. The influence of structural and non-structural calculatio...

Polyelectrolyte capsules consisting of a combination of biodegradable polyelectrolytes, dextran sulfate/polyarginine, and magnetic nanoparticles have been prepared. The possibility of changing the sizes and morphology of the capsules by heating their aqueous suspension has been investigated. The efficiency of capsule shrinking doesn’t change when a...

Experimental X-ray absorption spectra near the Fe K edge for as-synthesized MIL-88а metal–organic framework (MIL stands for Materials Institute Lavoisier) before and after activation have been obtained and analyzed for the first time. The theoretical analysis of experimental spectra has revealed changes in the local atomic structure of iron at the...

We report a two-step room temperature protocol for functionalization of copper-based metal–organic framework MOF-199, also known as HKUST-1, with gold nanoparticles. The resulted material is characterized with XRD, TEM, BET, UV–Vis and FTIR techniques building up a complete picture of its structural, electronic and vibrational properties. We also f...

After a short introduction highlighting the potentialities of metal–organic frameworks (MOFs) and the power of X-ray absorption spectroscopies (XAS), a list of selected examples follows. The first part of this review provides the basic concepts that are behind the most used XAS techniques: Extended X-ray Absorption Fine Structure (EXAFS) and X-ray...

Cobalt polypyridyls are highly efficient water‐stable molecular catalysts for hydrogen evolution. The catalytic mechanism explaining their activity is under debate and the main question is the involvement of pyridyls in the proton transfer: the pentapyridyl ligand, acting as a pentadentate ligand, can provide stability to the catalyst or one of the...

A set of Sm-doped iron oxide magnetic nanoparticles (FexOy NPs) of different size was synthesized by means of microware-assisted methods. Powder X-ray diffraction and transmission electron microscopy showed FexOy NPs with inverse spinel structure and high number of defects which are typical for small NPs. Mössbauer and X-ray absorption spectroscopy...

Herein, we report a novel one-step solvothermal synthesis of magnetite nanoclusters (MNCs). In this report we discuss synthesis, structure and properties of MNCs and contrast enhancement in T2-weighted MR images using magnetite nanoclusters. Effect of different organic acids, used as surfactants, on size and shape of MNC was investigated. Structure...

Functionalization of metal-organic frameworks with metal nanoparticles (NPs) is a promising way for producing advanced materials for catalytic applications. We present synthesis and in situ characterization of palladium NPs encapsulated inside functionalized UiO-67 metal-organic framework. The initial structure was synthesized with 10% of PdCl2bpyd...

A number of experimental techniques were used to study the changes in the atomic structure of copper(II) acetate-bipyridine under thermal decomposition between 25°C and 700°C to form copper-containing nanoparticles. The dynamics of structural changes during decomposition in a thermogravimetric chamber is compared with X-ray absorption spectra, IR s...

The first part of this chapter provides a simple, but general, description on the physical phenomena that are behind the interaction of probe beams (photons, electrons, or neutrons) with condensed matter. The differences in penetration depth, de Broglie wavelength, and requested sample environment for the three kinds of beams are stressed. The diff...

The Cu(II)–Gly–His–Lys (Glycyl–Histidyl–Lysine) complex is of interest as a model peptide to test the methodology for studying the structure of metal sites in proteins, in particular, the copper binding site in amyloid-β. X-ray absorption spectra of the Cu(II)GHK aqueous solution are measured. The stability of the complex under X-ray radiation is c...

In this chapter, we introduce MOFs as the new class of crystalline porous materials of remarkable potentialities. We underline the flexibility in the realization of different MOFs and the fact that they are ideal materials for performing X-ray absorption experiments at the metal K or L3 edges in transmission mode. A selection of relevant results ap...

Using microwave-assisted synthesis in organic solution, we produced magnetic γ-Fe2O3 nanoparticles covered with oleylamine and oleic acid.

Background Iron oxide nanoparticles have numerous and versatile biological properties, ranging from direct and immediate biochemical effects to prolonged influences on tissues. Most applications have strict requirements with respect to the chemical and physical properties of such agents. Therefore, developing rational design methods of synthesis of...

Solid solutions of zinc sulfide with manganese and cobalt are synthesized. Based on the analysis of X-ray diffraction profiles the conclusion is drawn about the formation of a hexagonal wurtzite type structure in the synthesized quantum dot (QD) solutions. The average crystallite sizes are 8 nm and 22 nm for the samples with manganese and cobalt re...

The microwave synthesis of quantum dots based on CdS has been performed, the temperature (T 180°C and 150°C) and synthesis duration (10 min and 5 min) have been varied. The analysis of the peak broadening in X-ray diffraction has shown that the average particle size in the synthesized samples is 10.02 nm for the CdST = 180°C sample and 5.22 nm for...

Cu(II) acetate-bipyridine complex has been synthesized. A series of experimental and theoretical spectroscopic studies was carried out for the freshly prepared sample. The local atomic and electronic structure was theoretically analyzed based on functional density theory and the structural models of the complex was obtained for various solvents. IR...

Colloidal quantum dots of the CdSe family have been studied by X-ray absorption near edge structure (XANES) spectroscopy and computer modelling. CdK edge XANES spectra in colloidal quantum dots based on varisized CdSe nanoparticles have been recorded. Atomic structure of CdSe particles and also CdSe particles doped by transition metal atoms Mn and...

Finite difference method (FDM) implemented in the FDMNES software [Phys. Rev. B, 2001, 63, 125120] was revised. Thorough analysis shows, that the calculated diagonal in the FDM matrix consists of about 96% zero elements. Thus a sparse solver would be more suitable for the problem instead of traditional Gaussian elimination for the diagonal neighbou...

There are two different motifs of X-ray absorption spectra for Cu(I) K-edge in amyloid-β peptide which could be due to two different configurations of local Cu(I) environment. Two or three histidine ligands can coordinate copper ion in varying conformations. On the other hand, oxidation of amyloid-β peptide could play an additional role in local co...

We synthesized UiO-67 Metal Organic Frameworks (MOFs) functionalized with bpydcPt(II)Cl2 and bpydcPt(IV)Cl4 complexes (bpydc = bipyridine-dicarboxylate), as attractive candidates for the heterogenization of homogeneous catalytic reactions. Pt L3-edge XAFS experiments allowed us to thoroughly characterize these materials, in the local environment of...

This review deals with key methods of synthesis and characterization of metal-organic frameworks (MOFs). The modular structure affords a wide variety of MOFs with different active metal sites and organic linkers. These compounds represent a new stage of development of porous materials in which the pore size and the active site structure can be modi...

Accurate modeling of the X-ray absorption near-edge spectra (XANES) is required to unravel the local structure of metal sites in complex systems and their structural changes upon chemical or light stimuli. Two relevant examples are reported here concerning the following: (i) the effect of molecular adsorption on 3d metals hosted inside metal?organi...

The ab initio computer design of the CdS-based quantum dots and the cobalt doped CdS quantum dots is carried out. The characteristics features of the atomic and electronic structures of semiconductor colloidal quantum dots on CdS of different sizes are studied, and the effect of cobalt impurity atoms is estimated. We have proved the sensitivity of...

By decreasing the size of semiconducting material the novel properties appear from the increased surface/bulk ratio and quantum confinement effects. X-ray absorption spectroscopy (XAS) can be applied to quantum dots and nanoparticles in-situ in the colloid, on the substrate or inside a solid matrix. The structural information about average size, ph...

Nanoscale local atomic structure determines most of unique properties of novel materials without long range order. To study its fine details one has to use both computer nanodesign and advanced experimental methods for nanodiagnostics. The status of modern theoretical analysis of the experimental x-ray absorption spectra to extract structural param...

The structure of Ce3+, which is responsible for the low-temperature oxygen storage capacity of ceria, was determined by high-energy-resolution fluorescence detected X-ray absorption spectroscopy at the Ce L-3 and L-1 edges. Well-defined ceria nanoparticles (rods, truncated octahedra, and cubes) were synthesized hydrothermally and promoted by platin...

Oxygen K-edge X-ray absorption, emission, and resonant inelastic X-ray scattering spectra were measured to site selectively gain insights into the electronic structure of aqueous zinc acetate solution. The character of the acetate ion and the influence of zinc and water on its local electronic structure are discussed.

This article is dedicated to the local atomic structure analysis of the copper binding site in amyloid-β peptide. Here we considered two possible structural models that were previously obtained by means of EXAFS analysis and density functional theory simulations. We present the calculations of Cu K-edge XANES spectra for both models and make compar...

Ce L1-edge high-energy-resolution fluorescence detected (HERFD) X-ray absorption spectroscopy (XAS) was applied to unravel the electronic structure of Pt-promoted CeO2 nanoparticles under different redox conditions. The Ce Lγ3 emission line was chosen for partial fluorescence yield detection to improve the XAS spectral resolution. Oxygen vacancies...

In the present work local surrounding of vanadium atoms in layered copper-chromium disulfides CuCr1 − x V x S2 is investigated using high-resolution X-ray absorption spectroscopy above vanadium K-edge. Based on experimental and theoretically simulated spectra comparison it is shown that vanadium atoms replace chromium ones even at high concentratio...

The significant deviation from the ideality of dimethyl sulfoxide (DMSO)/water mixtures can be addressed based on the change of the local molecular orbitals of each solvent upon mixing. Oxygen K-edge absorption and emission spectra of DMSO/water solutions were measured using the liquid microjet technique. The spectra demonstrate that the hydrogen b...

The polar character of the sulfinyl bond, which determines many of the properties of dimethyl sulfoxide (DMSO), is a result of charge transfer in low-lying π-type orbitals. This characteristic-together with the wide energy gap between the highest occupied and the lowest unoccupied molecular orbitals of this substance-makes DMSO a relatively inert a...

Dips appearing in the L-edge total fluorescence yield (TFY) spectra of transition-metal ions in aqueous solutions have been recently attributed to, orbital mixing of the solute with the solvent orbitals. Here we compare the L-edge TFY, Oxygen Kα and Co2+ Ll(3s → 2p3/2), Lη(3s → 2p1/2), Lα(3d → 2p3/2) and Lβ(3d → 2p1/2) –edge partial fluorescence yi...