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Search results for: srtio3
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TiO2 /SrTiO3 and SrTiO3 microspheres decorated with Rh, Ru or Pt nanoparticles: Highly UV–vis responsible photoactivity and mechanism
PublicationA series of TiO2/SrTiO3 and SrTiO3 microspheres decorated by Rh, Ru or Pt NPs were prepared by facile hydrothermal method. The as-prepared samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) with energy-dispersive Xray (EDX) spectroscopy, scanning electron microscopy (SEM), photoluminescence spectrometry (PL), Fourier transform infrared (FT-IR) and...
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Electrical and structural properties of Nb-doped SrTiO3
PublicationNiobium-doped strontium titanate synthesized via conventional solid-state reaction has been studied. Influence of niobium content on the lattice parameters and electrical conductivity has been reported. Various reduction conditions have been investigated. For samples reduced in hydrogen at 1400°C, a transition from thermally activated to metallic behavior has been observed. Maximum electrical conductivity (ca. 55 Scm−1 at 650°C)...
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The effect of imidazolium ionic liquid on the morphology of Pt nanoparticles deposited on the surface of SrTiO3 and photoactivity of Pt–SrTiO3 composite in the H2 generation reaction
PublicationPhotocatalytic water splitting has great potential in solar-hydrogen production as a low-cost and environmentally friendly method. Different unique techniques used to obtain photocatalysts with various modifications to improve H2 generation have been introduced. In the present work, SrTiO3 was successfully synthesized via the solvothermal method in the presence of ionic liquid (IL) - 1-butyl-3-methylimidazolium bromide ([BMIM][Br])...
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Electrical and structural properties of Nb-doped SrTiO3 ceramics
PublicationPrzebadano wpływ zawartości niobu na strukturę i własności elektryczne tytanianu strontu. Zbadany został wpływ warunków redukcji i porowatości na właściwości materiału. Za optymalne uznano domieszkowanie niobem w wysokości 2% molowych.
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Applicability of Gd-doped BaZrO3, SrZrO3, BaCeO3 and SrCeO3 proton conducting perovskites as electrolytes for solid oxide fuel cells
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Effects of Sr/Ti stoichiometry in SrTiO3-based SOFC anodes
PublicationScharakteryzowano wpływ stechiometrii Sr/Ti na właściwości strukturalne, elektryczne i mechaniczne anod na bazie tytanianu strontu. Wyjaśniono genezę niektórych zjawisk w oparciu o chemię defektów związków niestechiometrycznych na bazie istniejących pozycji literaturowych.
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Fabrication and structural properties of Y and Fe co-doped SrTiO3 nanoceramics for SOFC
PublicationYttria and iron co-doped strontium titanate perovskites, (Y0,07Sr0,93Ti1-xFexO3-δx=0,1; 0,2) samples were fabricated by two methods: solid-state synthesis (SS) and the Pechinisol-gel modified method. The morphology of samples were measured by SEM and X-raydiffraction. Results were compared and discussed. The strong relationship between fabricationprocedure and microstructure has been proven. It was also observed, that the nanoceramicsobtained...
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Studies on novel BiyXz-TiO2/SrTiO3 composites: Surface properties and visible light-driven photoactivity
PublicationA series of novel BiyXz-TiO2/SrTiO3 composites were prepared by multistep synthesis route. The asprepared photocatalysts were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), diffuse reflectance spectroscopy (DRS), Fourier transform infrared (FT-IR), Raman spectra and BET analysis. The photocatalytic activity test was performed in aqueous solution of phenol under...
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Visible light photocatalysis employing TiO2/SrTiO3-BiOI composites: Surface properties and photoexcitation mechanism
PublicationA series of binary TiO2/SrTiO3 and ternary TiO2/SrTiO3_BiOI composites have been synthesized using multistep preparation method. Characterization of the obtained photocatalysts covered complex analysis including morphology + y (SEM), BET specific surface area, porosity, optical properties (DRS), chemical composition of surface (XPS), crystal structure and crystal size (XRD). UV–vis and Vis ligh induced photocatalytic activity was...
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Structural and electrical properties of Cr-doped SrTiO 3 porous materials
PublicationSeries of single-phase materials with assumed formula SrTi1−xCrxO3 (where x = 0, 1, 4, 6 mol.%) were obtained by sol-gel method. The structure and microstructure of materials were characterised by X-ray diffraction and scanning electron microscopy methods. Moreover, the study of electrical properties and evaluation of chemical stability in CO2/H2O atmosphere was performed by electrochemical impedance spectroscopy and thermogravimery...
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Characterization methods of nickel nano-particles obtained by the ex-solution process on the surface of Pr, Ni-doped SrTiO3 perovskite ceramics
PublicationIn this paper, a novel electrode material based on Pr, Ni co-doped strontium titanate ( Sr0.7Pr0.3)xTi1−yNiyO3 with constant amount of 30% praseodymium dopant, different amount of nickel (y = 0.06 and y = 0.10) and additional nonstoichiometry in Sr-site (x = 1; x = 0.9 and x = 0.8) was investigated as fuel electrode for SOEC devices. A porous ceramics were prepared by solid-state reaction method. X-ray diffraction measurements...
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Badanie ogniwa paliwowego typu SORC z anodą na bazie perowskitu SrTi03
PublicationPublikacja naukowa opisująca budowę i badanie ogniwa paliwowego typu SOFC zbudowanego na elektrolicie z zastosowaniem anody na bazie domieszkowanego donorowo tytanianu strontu.
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Indium doping in SrCeO3 proton-conducting perovskites
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Nanostructure and dielectric behavior of vanadate glasses containing BaTiO3
PublicationThe ac and dc electrical conductivity of barium titanate doped bismuth-vanadate as-quenched and heat-treated materials was measured in the frequency range from 1 mHz to 1 MHz and in the temperature range from 153 K to 423 K with the impedance spectroscopy method. The microstructure was investigated by means of XRD, scanning electron microscopy (SEM), atomic force microscopy (AFM) and confocal microscopy. The obtained results showed...
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Magnetoelectric, spectroscopic, optical and elastic properties of Co-doped BaTiO3 ceramics
Publicationhe BaTiO3 perovskite is widely used in the electronic technology due to its dielectric, piezoelectric and ferroelectric properties and is a well-known base for obtaining a promising multifunctional material. In this paper we report the extensive studies on the Co-doped BaTiO3 ceramics for the wide range cobalt content. Full structural characterization of studied samples in a 20–450 K range was provided. The results of research...
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Magnetoelectric effect in (BiFeO3)x–(BaTiO3)1-x solid solutions
PublicationThe aim of the present work was to study magnetoelectric effect (ME) in (BiFeO3)x–(BaTiO3)1x solid solutions in terms of technological conditions applied in the samples fabrication process. The rapidly growing interest in these materials is caused by their multiferroic behaviour, i.e. coexistence of both electric and magnetic ordering. It creates possibility for many innovative applications, e.g. in steering the magnetic memory...
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Microstructural and electrical properties of Y0.07Sr0.93-xTiO3 perovskite ceramics
PublicationIn order to find a relationship between electrical and microstructural properties, yttrium-doped strontium titanate (7 mol%) with various values of strontium nonstoichiometry was investigated and shown in this work. It has been observed that yttrium doping can affect the electrical properties of SrTiO3 to a great extent. Moreover, the microstructural and electrical properties can be influenced by strontium nonstoichiometry. The...
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Donor-substituted SrTi1+xO3−δ anodes for SOFC
PublicationNonstoichiometric Nb-substituted SrTiO3 compounds were investigated in order to discuss the influence of nonstoichiometry at the sample properties in the light of recent results reported in the literature. Structural and electrical properties of samples were characterized. Investigated compounds were also applied as anodes for Solid Oxide Fuel Cells and their reactivity with YSZ electrolyte was examined. The defect chemistry explaining...
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Donor-substituted SrTi1+xO3−δ anodes for SOFC
PublicationPrzebadano wpływ niestechiometrii na właściwości tytanianu strontu domieszkowanego niobem. Zaproponowano chemię defektów dla tego typu związków.
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Lanthanide ions (Eu3+, Er3+, Pr3+) as luminescence and charge carrier centers in Sr2TiO4
PublicationA series of strontium orthotitanate (Sr2TiO4) samples doped with 2% of a mole of europium, praseodymium, and erbium were obtained using the solid-state synthesis method. The X-ray diffraction (XRD) technique confirms the phase purity of all samples and the lack of the influence of dopants at a given concentration on the structure of materials. The optical properties indicate, in the case of Sr2TiO4:Eu3+, two independent emission...
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Microstructural and electrical properties of Y0.07Sr0.93-xTiO3-δ perovskite ceramics
PublicationIn order to find a relationship between electrical and microstructural properties, yttrium-doped strontiumtitanate (7 mol%) with various values of strontium nonstoichiometry was investigated and shown in this work.It has been observed that yttrium doping can affect the electrical properties of SrTiO3 to a great extent.Moreover, the microstructural and electrical properties can be influenced by strontium nonstoichiometry.The defect...
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Microstructural and electrical properties of Y0:07Sr0:93−xTiO3− perovskite ceramics
PublicationIn order to find a relationship between electrical and microstructural properties, yttrium-doped strontium titanate (7 mol%) with various values of strontium nonstoichiometry was investigated and shown in this work. It has been observed that yttrium doping can affect the electrical properties of SrTiO3 to a great extent. Moreover, the microstructural and electrical properties can be influenced by strontium nonstoichiometry. The...
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Thermochemistry of rare earth perovskites Na3xRE0.67−xTiO3 (RE = La, Ce)
PublicationHigh-temperature oxide melt solution calorimetry using sodium molybdate (3Na2O·4MoO3) solvent at 973 K was performed for the Na3xRE0.67−xTiO3 (RE = La, Ce) perovskite series. The enthalpies of formation of lanthanum perovskites from oxides (La2O3, Na2O, TiO2), are −107.25 ± 2.56, −93.83 ± 6.06, −80.68 ± 5.93, and −33.49 ± 4.26 kJ/mol and enthalpies of formation from elements are −1614.05 ± 5.37, −1596.44 ± 7.68, −1594.03 ± 7.58,...
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Structural Properties and Water Uptake of SrTi1−xFexO3−x/2−δ
PublicationIn this work, Fe-doped strontium titanate SrTi1−xFexO3−x/2−δ, for x = 0–1 (STFx), has been fabricated and studied. The structure and microstructure analysis showed that the Fe amount in SrTi1−xFexO3−x/2−δ has a great influence on the lattice parameter and microstructure, including the porosity and grain size. Oxygen nonstoichiometry studies performed by thermogravimetry at different atmospheres showed that the Fe-rich compositions...
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Impedance spectroscopy of BaTiO3 cubes suspended in lossy liquids as a physical model of two-phase system
PublicationTechniki spektroskopii impedancyjnej zostały wykorzystane do analizy modelu fizycznego w układzie dwufazowym w celu wyznaczanie stałej dielektrycznej dielektryka umieszczonego w cieczy. Badania eksperymentalne przeprowadzono z użyciem BaTiO3 jako materiału dielektrycznego, który został przygotowany jako kostki o jednakowej wielkości 2x2x1 mm3.
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GNSS reference solution for permanent sition stability monitoring and geodynamical investigations - the ASG-EUPOS case study
PublicationThe aim of this paper is to present the strategy of determination of the reference solution for the ASG-EUPOS (ActiveGeodetic Network – European Position Determination System) coordinate monitoring system. ASG-EUPOS is a network of permanent GNSS (Global Navigation Satellite System) stations controlled by the Polish Head Office of Geodesy and Cartography (HOGC), which main role is to realize the ETRS89 (European Terrestrial Reference...
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The Influence of Iron Doping on Performance of SrTi1-XFexO3-δ Perovskite Oxygen Electrode for SOFC
PublicationSolid Oxide Fuel Cells (SOFC) are based on electrolytes and mixed ionic and electronic conductivity (MIEC) materials. The need to reduce costs causes an increase in interest of new compounds suitable for operating temperatures between 600 °C and 800 °C. The SrTi1-xFexO3 (STF) perovskite material is a perspective material that could be used for the oxygen electrodes. In this work STF materials with different content of iron (x =...
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ALTERNATIVE, DIRECT SYNTHESIS METHOD OF THE CERAMIC SOLID SOLUTIONS BASED ON BaTiO3 THROUGH A HIGH ENERGY BALL MILLING
PublicationPolycrystalline samples BaTiO3 and the solid solutions Ba0.9Sr0.1TiO3, Ba0.9Sr0.1Ti0.9Sn0.1O3, Ba0.9Sr0.1Ti0.8Sn0.2O3 were obtained by means of a mechanochemical treatment based on the high-energy ball milling technique and next a high temperature solid state reaction method. The influence of synthesis condition on microstructural, dielectric and ferroelectric properties of obtained solid solutions were investigated. The structure...
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Stannates, titanates and tantalates modified with carbon and graphene quantum dots for enhancement of visible-light photocatalytic activity
PublicationMost efforts in heterogeneous photocatalysis are focused on development of new and stable photoactive materials efficient in degradation of various pollutants under visible-light irradiation. In this regard, the wide-bandgap perovskite semiconductors, i.e., SrTiO3 (titanate), SrSnO3 (stannate) and AgTaO3 (tantalate), were prepared by a solvothermal method, and then modified with carbon quantum dots (CQDs) or graphene quantum dots...
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Correlation between structural and electrical properties in highly porous (Y,Sr)(Ti,Nb)O3-delta SOFC anodes
PublicationIn order to find a relationship between structural and electrical properties, niobium and yttrium doped SrTiO3 ceramics were prepared via solid-state reaction. The samples were sintered in hydrogen and air conditions. The samples were also fabricated with a pore-former to obtain highly porous specimens. The electrical properties of Nb-doped SrTiO3 samples and yttrium and niobium co-doped SrTiO3 were compared. The comparable electrical...
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Effect of sintering temperature on electrochemical performance of porous SrTi1-xFexO3-δ (x = 0.35, 0.5, 0.7) oxygen electrodes for solid oxide cells
PublicationThis work evaluates the effects of the sintering temperature (800 °C, 900 °C, 1000 °C) of SrTi1-xFexO3-δ (x = 0.35, 0.5, 0.7) porous electrodes on their electrochemical performance as potential oxygen electrode materials of solid oxide cells. The materials were prepared by a solid-state reaction method and revealed the expected cubic perovskite structure. After milling, the powders were characterised by a sub-micrometre particle...
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Właściwości strukturalne i katalityczne domieszkowanych związków typu SrTi(1-x)Fe(x)O3
PublicationPublikacja naukowa opisująca wytwarzanie i badanie właściwości strukturalnych i katalitycznych domieszkowanego itrem i żelazem tytanianu strontu.
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The effect of Fe on chemical stability and oxygen evolution performance of high surface area SrTix-1FexO3-δ mixed ionic-electronic conductors in alkaline media
PublicationDevelopment of environmentally friendly, high performing oxygen evolution reaction (OER) catalysts is an important research challenge. In this work, iron doped strontium titanates with a general formula SrTi1-xFexO3-δ (x = 0.35, 0.50, 0.70, 0.90, and 1.00) denoted as STFx, were synthesized via a solid state reaction technique and characterized in terms of oxygen evolution reaction electrocatalysis in an alkaline electrolyte (0.1...
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Cu supported on various oxides as a candidate catalyst for dry methane reforming in DIR-SOFCs systems
PublicationA series of Cu-support systems were tested as potential candidates for DIR-SOFC (Direct Internal Reforming SOFC) catalysts towards a dry reforming of methane (DRM). The various supports (-Al2O3, CeO2, ZrO2, SrTiO3) with comparable specific surface area (SSA), and additionally -Al2O3 with SSA an order of magnitude larger than that of the other supports has been applied. The obtained Cu-support systems were characterized in terms...
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Modyfikowany tytanian strontu jako anoda do tlenkowych ogniw paliwowych typu sofc
PublicationPublikacja przeglądowa na temat sposobu modyfikacji materiału anodowego opartego na bazie perowskitu SrTiO3 pod względem możliwości zastosowania w ogniwach typu SOFC
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Synthesis and structural properties of (Y, Sr)(Ti, Fe, Nb)O3−δ perovskite nanoparticles fabricated by modified polymer precursor method
PublicationThe yttrium, iron and niobium doped-SrTiO3 powders have been successfully fabricated by a modified low–temperature synthesis method from a polymer complex. The usage of strontium hydroxide precursor instead of conventional strontium nitrate or strontium carbonate provides to the possibility of significant decrease of annealing temperature. It allows to prepare a material with sphere-shape grains of nanometric size (15–70 nm). The...
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Structural and electrical properties of Sr(Ti,Fe)O3-δ materials for SOFC cathodes
PublicationW niniejszym artykule, dwa związki SrTiO3 domieszkowanego Fe przebadano pod względem przydatności na katody w tlenkowych ogniwach paliwowych. SrTi0.65Fe0.35O3 i SrTi0.5Fe0.5O3 zostały przebadane pod względem reaktywności chemicznej z elektrolitem YSZ. Stwierdzono, że przewodnictwo elektryczne tych związków jest stosunkowo niskie: 0,4 S/cm i 2 S/cm odpowiednio dla STF35 i STF50.
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Various types of semiconductor photocatalysts modified by CdTe QDs and Pt NPs for toluene photooxidation in the gas phase under visible light
PublicationA novel synthesis process was used to prepare TiO2 microspheres, TiO2 P-25, SrTiO3 and KTaO3 decorated by CdTe QDs and/or Pt NPs. The effect of semiconductor matrix, presence of CdTe QDs and/or Pt NPs on the semiconductor surface as well as deposition technique of Pt NPs (photodeposition or radiolysis) on the photocatalytic activity were investigated. The as-prepared samples were characterized by X-ray powder diffractometry (XRD),...
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Interactions between components of SrTi0.98 Nb0.02O3-δ-YSZ and SrTi0.98 Nb0.02O3-δ -CeO2 composites
PublicationComposites consisting of SrTiO3-based perovskite and either yttria-stabilized zirconia or ceria were investigated. The mechanical compatibility and possible inter-diffusion between phases were characterized by scanning electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy. A gradual disappearance of Ce-containing phases with an increase in the temperature of reduction in hydrogen was noticed. Moreover,...
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Mössbauer Spectroscopy and Magnetoelectric Effect Studies of Multiferroic Ceramics Based on BiFeO<sub>3</sub>
PublicationIn this work the results of investigations for (BiFeO3)x(BaTiO3)1-x and Bi1-xNdxFeO3 solid solutions are described. Samples were prepared by the conventional solid-state sintering method. X-ray diffraction, 57Fe Mössbauer spectroscopy, and magnetoelectric effect measurements were applied as complementary methods to determine the structure and magnetic properties of materials. For (BiFeO3)x(BaTiO3)1-x solid solutions Mössbauer...
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KTaO3-based nanocomposites for air treatment
PublicationA series of single semiconductors and their nanocomposites combination (such as KTaO3 + CdSe + SrTiO3; KTaO3 + CdS +WO3; KTaO3 + CdS + MoS2) were prepared using hydrothermal route. Photocatalytic activity of as-prepared nanocomposites was estimated by photocatalytic degradation of toluene in the gas phase using light-emitting diodes (LEDs, 375 nm) in four subsequent cycles. The nanocomposites were characterized by scanning electron...
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The optical and electrical properties of nanocrystalline La0.4Sr0.6TiO3 thin films.
PublicationW pracy badano wpływ mikrostruktury cienkich filmów La0.8Sr0.6TiO3 na właściwości optyczne. Gęste filmy o grubości około 200nm były przygotowane na szafirze z prekursorów polimerowych metodą wirową. Filmy były wypalone w temperaturze 500-800 stC. Badania rentgenowskie wskazały utworzenie kubicznej struktury perowskitowej podobnej do niedomieszkowanego SrTiO3. Wielkość ziaren zależała od temperatury wypalenia osiągając 30nm w 800stC....
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Preparation and photocatalytic properties of BaZrO 3 and SrZrO 3 modified with Cu 2 O/Bi 2 O 3 quantum dots
PublicationIn this study, we report a novel method of BaZrO3 and SrZrO3 surface modification by two different types of quantum dots (QDs, Cu2O and Bi2O3), which improved the photocatalytic performance of the obtained materials under UV-Vis light irradiation. Pristine BaZrO3 and SrZrO3 were prepared by the hydrothermal method. The deposition of Cu2O- and Bi2O3-QDs was carried out by chemical reduction. The morphology of the nanoparticles was...
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Structural and electrical transport properties of Pr-doped SrTi0.93Co0.07O3-δ a novel SOEC fuel electrode materials
PublicationSolid Oxide Electrolyzer Cells (SOECs) are very promising electrochemical devices for the production of syngas (H2/CO) by H2O and CO2 co-electrolysis. The structure, microstructure and electrical properties of the fuel electrode material play a crucial role in the performance of the whole cell and efficiency of electrocatalytic reduction of steam into hydrogen. In the present work, a novel Co and Pr co-doped SrTiO3-δ material attracted...
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Enhanced Spectroscopic Insight into Acceptor-Modified Barium Strontium Titanate Thin Films Deposited via the Sol–Gel Method
PublicationIn the present paper, composite thin films of barium strontium titanate (BaxSr1−xTiO3) with an acceptor modifier (magnesium oxide—MgO) were deposited on metal substrates (stainless steel type) using the sol–gel method. The composite thin films feature BaxSr1−xTiO3 ferroelectric solid solution as the matrix and MgO linear dielectric as the reinforcement, with MgO concentrations ranging from 1 to 5 mol%. Following thermal treatment...
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Exsolution of Ni nanoparticles on the surface of cerium and nickel co-doped lanthanum strontium titanate as a new anodic layer for DIR-SOFC. Anti-coking potential and H2S poisoning resistance of the prepared material
PublicationThe aim of this study was to evaluate a new catalytic material for biogas fueled DIR-SOFC. This material was a perovskite-type SrTiO3 doped with La, Ce and Ni of a general formula La0.27Sr0.54Ce0.09Ni0.1Ti0.9O3-σ (LSCNT). Additional preparation steps were undertaken to promote a nickel exsolution process. Heat post-treatment of powders in a humidified H2 resulted in an intensive growth of nickel nanoparticles (NPs) while the temperature...
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CGO as a barrier layer between LSCF electrodes and YSZ electrolyte fabricated by spray pyrolysis for solid oxide fuel cells
PublicationPerovskite La0.6Sr0.4Co0.2Fe0.8O3 − δ (LSCF) is often used as a cathode material for solid oxide fuel cells (SOFC) due to high mixed ionic and electronic conductivity and good catalytic activity. Unfortunately, sintering of the LSCF cathode together with the yttria stabilized zirconia (YSZ) electrolyte, leads to formation of the La2Zr2O7 and SrZrO3 phases in the interface. These phases increase the resistance of the cell. To avoid...
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Interaction of SrTi0.65Fe0.35O3-δ with LaNi0.6Fe0.4O3-δ, La0.6Sr0.4Co0.2Fe0.8O3-δ and Ce0.8Gd0.2O2-δ
PublicationIron doped strontium titanates SrTi1-xFexO3-δ are perovskites of versatile properties. They can be used in solid oxide fuel cells or high temperature oxygen sensors. Their reactivity with electrolyte materials, cathode buffer layer materials, other cathode materials or current collector layers has not been fully tested. In this study we use X-ray diffraction to check SrTi0.65Fe0.35O3-δ compatibility with Ce0.8Gd0.2O2-δ (used as...
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Fabrication and Crystal Structure of Sol-Gel Deposited BST Thin Films with Compositional Gradient
PublicationIn the present research technology of compositionally graded barium strontium titanate Ba1-xSrxTiO3 thin films deposited on stainless steel substrates by sol-gel spin coating followed with thermal annealing at T = 650°C is reported. Results of thermal behavior of the sol-gel derived powders with compositions used for fabrication of graded structure (i.e. with Sr mole fraction x = 0.5, 0.4 and 0.3) are described. X-ray diffraction...
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A model of fuel combustion process in the marine reciprocating engine work space taking into account load and wear of crankshaft-piston assembly and the theory of semi-Markov processes
PublicationThe ar ticle analyses the operation of reciprocal internal combu stion engines, with mar ine engines u sed a s an example. The analysis takes into account types of energy conversion in the work spaces (cylinders) of these engines, loads of their crankshaft-piston assemblies, and types of fuel combustion which can take place in these spaces during engine operation. It is highlighted that the analysed time-dependent loads of marine...