Physico-Chemical Properties of NaVO Prepared by Solid-State Reaction.

Sodium-vanadium oxide NaVO is synthesized via solid-state method and optimum synthesis conditions are chosen based on the data of DSC and TG analysis. The material synthesized is characterized by X-ray phase analysis, Raman spectroscopy and scanning electron microscopy. The ratio V/V in the sample obtained is determined by X-ray photoelectron spectroscopy.

Lithium-Cation Conductivity of Solid Solutions in LiZrAO (A = Nb, Ta) Systems.

LiZrAxO (A = Nb; Ta) system with 0 < x < 0.30 is synthesized by glycine-nitrate method. Boundaries of solid solutions based on monoclinic LiZrO are determined; temperature (200-600 °C) and concentration dependences of conductivity are investigated.

An Ab Initio Study of Lithization of Two-Dimensional Silicon-Carbon Anode Material for Lithium-Ion Batteries.

This work is devoted to a first-principles study of changes in the structural, energetic, and electronic properties of silicene anodes during their lithium filling. Anodes were presented by silicene on carbon substrate and free-standing silicene. The ratio of the amount of lithium to silicon varied in the range from 0.

Investigation of the Quasi-Binary Phase Diagram FLiNaK-NdF.

The NdF solubility in molten eutectic FLiNaK, which is a conceivable medium for a molten salt reactor (MSR), was determined by the quasi-binary phase diagram FLiNaK-NdF. The eutectic mixture FLiNaK was prepared by direct melting of components LiF, NaF and KF·HF. The acidic anhydrous salt (KF·HF) was used instead of the hygroscopic KF.

Simulation of 3D Electrochemical Phase Formation: Mixed Growth Control.

Processes of nucleation and growth largely determine the structure and properties of thin films obtained by electrodeposition on foreign substrates. Theoretical aspects of the initial stages of electrochemical phase formation under constant and variable overpotentials are considered in this work. Simulation of multiple nucleation with mixed (charge transfer, and diffusion) controlled growth was performed for three cases (cyclic voltammetry, potentiostatic electrodeposition, and galvanostatic electrodeposition).

Simultaneous Hetero- and Isovalent Doping as the Strategy for Improving Transport Properties of Proton Conductors Based on BaLaInO.

This work focused on the novel electrochemical energy material with significantly improved electrical properties. The novel complex oxide BaLaInYO with layered perovskite structure was obtained for the first time. It was proven that the simultaneous introduction of barium and yttrium ions in the structure of BaLaInO leads to the increase in the unit cell volume of up to 4% and water uptake by about three times.

Nanostructure Engineering of Metal-Organic Derived Frameworks: Cobalt Phosphide Embedded in Carbon Nanotubes as an Efficient ORR Catalyst.

Heteroatom doping is considered an efficient strategy when tuning the electronic and structural modulation of catalysts to achieve improved performance towards renewable energy applications. Herein, we synthesized a series of carbon-based hierarchical nanostructures through the controlled pyrolysis of Co-MOF (metal organic framework) precursors followed by in situ phosphidation. Two kinds of catalysts were prepared: metal nanoparticles embedded in carbon nanotubes, and metal nanoparticles dispersed on the carbon surface.

Synthesis of a PdIn-PdIn bi-continuous nanoporous structure by electrochemical dealloying in molten salts.

A study of the high-temperature electrochemical selective dissolution of PdIn intermetallics in molten mixtures of alkali chlorides with the formation of nanoporous structures has been carried out to obtain a coherent structure consisting of PdIn and PdIn intermetallics. The smallest pore size (approximately 100 nanometers) with a bi-continuous structure of PdIn-PdIn is obtained from the PdIn intermetallic phase at a temperature of 450 °C and a current density of 50 mA cm in a molten LiCl-KCl eutectic. It has been shown that the temperature of the anodic dissolution process is the most important factor in controlling the pore size and structural morphology.

A Potential-Induced Transformation in the Double Electrical Layer on the Rhenium Electrode in Alkali Chloride Melts.

Structural transformations in the adsorption layer caused by an electric potential are investigated using the experimental data on the capacitance of a double electric layer for a rhenium electrode in molten sodium, potassium and cesium chlorides at 1093 K. Likening the double electric layer to a flat capacitor, as well as the effective length of the shielding of the electrode charge and changes in the charge sign depending on the applied potential are estimated. It is found that near the minimum potential of the capacitance curve, the shielding length decreases proportionally to the square of the potential due to the deformation of the double layer.

Electrochemical Production of Bismuth in the KCl-PbCl Melt.

An anode dissolution of binary metallic lead-bismuth alloys with different concentrations of components has been studied in the KCl-PbCl molten eutectic. The dissolution of lead is found to be a basic process for the alloys of Pb-Bi (59.3-40.

Opportunities, Challenges and Prospects for Electrodeposition of Thin-Film Functional Layers in Solid Oxide Fuel Cell Technology.

Electrolytic deposition (ELD) and electrophoretic deposition (EPD) are relevant methods for creating functional layers of solid oxide fuel cells (SOFCs). This review discusses challenges, new findings and prospects for the implementation of these methods, with the main emphasis placed on the use of the ELD method. Topical issues concerning the formation of highly active SOFC electrodes using ELD, namely, the electrochemical introduction of metal cations into a porous electrode backbone, the formation of composite electrodes, and the electrochemical synthesis of perovskite-like electrode materials are considered.

Activation of Porous Pt Electrodes Deposited on YSZ Electrolyte by Nitric Acid Treatment.

The effect of nitric acid treatment on the electrochemical performance of porous Pt electrodes deposited on YSZ (abbreviation from yttria stabilized zirconia) electrolyte was investigated. Two identical symmetrical Pt/YSZ/Pt cells with porous Pt electrodes were fabricated, after which the electrodes of the first cell were kept as sintered, while those of the second cell were impregnated with HNO solution. The electrochemical behavior of the prepared electrodes was studied using impedance spectroscopy and cyclic voltammetry.

Study of the structure of a multicomponent salt melt using molecular dynamics modeling.

The composition of the electrolyte is critical in the electrodeposition of high-purity silicon. In this work, molecular dynamics modeling of the preparation of liquid salt melt KF-KCl-KI and a detailed study of its structure based on the method of statistical geometry have been performed. Partial radial distribution functions reflect the size of the ions under consideration and the averaged structure of the generated ionic subsystems.

Structural and spectroscopic characterization of a new series of BaREGeO (RE = Pr, Nd, Gd, and Dy) and BaGdEuGeO tetragermanates.

A new series of BaREGeO (RE = Pr, Nd, Gd, Dy) germanates and BaGdEuGeO (x = 0.1-0.8) solid solutions have been synthesized using the solid-state reaction technique and characterized by X-ray powder diffraction.

Correlation between structure, surface defect chemistry and O/O exchange for LaMoO and La(MoO).

The LaMoO and La(MoO) powders were synthesized using a solid-state reaction method and used to prepare dense ceramics. X-ray photoelectron spectroscopy was used to study the chemical composition and charge numbers of the elements in the subsurface area of dense ceramics of lanthanum molybdates. The spectra were measured under an ultra-high vacuum of 7 × 10 atm at 30 °C and 600 °C, and under an oxygen atmosphere at 2 × 10 atm at 600 °C and 825 °C.

Effect of grain boundaries in LaSrCoO on oxygen diffusivity and surface exchange kinetics.

The single crystal and polycrystalline specimens of La0.84Sr0.16CoO3-δ oxide were synthesized and characterized by X-ray powder diffraction analysis, energy dispersive X-ray microanalysis, the electron backscatter diffraction technique, and X-ray photoelectron spectroscopy.

Novel Mn-/Co-N Moieties Captured in N-Doped Carbon Nanotubes for Enhanced Oxygen Reduction Activity and Stability in Acidic and Alkaline Media.

Fe-N-C-based electrocatalysts have been developed as an encouraging substitute compared to their expensive Pt-containing equivalents for the oxygen reduction reaction (ORR). However, they still face major durability challenges from the in- situ production of Fenton radicals. Therefore, the synthesis of Fe-free ORR catalysts is among the emerging concerns.

Emerging materials for the electrochemical detection of COVID-19.

The SARS-CoV-2 virus is still causing a dramatic loss of human lives worldwide, constituting an unprecedented challenge for the society, public health and economy, to overcome. The up-to-date diagnostic tests, PCR, antibody ELISA and Rapid Antigen, require special equipment, hours of analysis and special staff. For this reason, many research groups have focused recently on the design and development of electrochemical biosensors for the SARS-CoV-2 detection, indicating that they can play a significant role in controlling COVID disease.

Undoped SrMMoO Double Perovskite Molybdates (M = Ni, Mg, Fe) as Promising Anode Materials for Solid Oxide Fuel Cells.

The chemical design of new functional materials for solid oxide fuel cells (SOFCs) is of great interest as a means for overcoming the disadvantages of traditional materials. Redox stability, carbon deposition and sulfur poisoning of the anodes are positioned as the main processes that result in the degradation of SOFC performance. In this regard, double perovskite molybdates are possible alternatives to conventional Ni-based cermets.

Atomic Scale Mechanisms of Multimode Oxide Growth on Nickel-Chromium Alloy: Direct Observation of the Initial Oxide Nucleation and Growth.

The initial growth mode of oxide on alloy plays a decisive role in the development of protective oxide scales on metals and alloys, which is critical for their functionality for high temperature applications. However, the atomistic mechanisms dictating that the oxide growth remain elusive due to the lack of direct observation of the initial oxide nucleation and growth at atomic-scale. Herein, we employed environmental transmission electron microscopy and the first-principles calculations to elucidate the initial atomic process of nickel-chromium (Ni-Cr) alloy oxidation.

Progress in Modern Marine Biomaterials Research.

The growing demand for new, sophisticated, multifunctional materials has brought natural structural composites into focus, since they underwent a substantial optimization during long evolutionary selection pressure and adaptation processes. Marine biological materials are the most important sources of both inspiration for biomimetics and of raw materials for practical applications in technology and biomedicine. The use of marine natural products as multifunctional biomaterials is currently undergoing a renaissance in the modern materials science.

The interaction of defects in a mayenite structure.

Calcium aluminate Ca12Al14O33 initially known as cement compound after a series of structural refinements presented a complex cubic structure. It demonstrates a surprising feature consisting of the occurrence of spherical cavities named as cages. After this, mayenite is regarded as a kind of anti-zeolite.

Progress in chitin analytics.

Chitin is the second most abundant biopolymer and functions as the main structural component in a variety of living organisms. In nature, chitin rarely occurs in a pure form, but rather as nanoorganized chitin-proteins, chitin-pigments, or chitin-mineral composite biomaterials. Although chitin has a long history of scientific studies, it is still extensively investigated for practical applications in medicine, biotechnology, and biomimetics.

Effect of saturation on the viscoelastic properties of dentin.

This paper focuses on the analysis and quantitative characterization of the effect of saturation on the viscoelastic properties of human root dentin. Uniaxial compression tests under creep conditions have been performed on root molar dentin with tubules fully saturated with a viscous physiological fluid, as well as samples with non-saturated tubules (dry dentin samples). Blair-Rabotnov (BR) fraction-exponential model is used to characterize the overall viscoelastic properties of dentin and correlate them to the level of saturation.

Novel Bifunctional VO Nanosheets Coupled with N-Doped-Carbon Encapsulated Ni Heterostructure for Enhanced Electrocatalytic Oxidation of Urea-Rich Wastewater.

Developing high performance bifunctional transition metal catalysts would be significantly beneficial for electrocatalytic oxidation of urea-rich wastewater. Herein, we synthesize a VO nanosheet anchored N-doped-carbon encapsulated Ni heterostructure (Ni@C-VO/NF) for the reactions of urea oxidation (UOR) and hydrogen evolution (HER). Electrochemical results indicate that it exhibits small potentials of 1.