Complex oxides with a spinel structure can be considered as promising electrolyte materials for electrochemical devices to be used in energy generation. In this paper, complex oxides with a spinel structure were obtained, and their electrical conductivity properties at various pH2O and pO2 were investigated for the first time. These compositions are unstable in a humid atmosphere and decompose to barium hydroxide and metal oxide. The electrical conductivity values of BaNd2O4 and BaSm2O4 spinels must be measured strictly in an atmosphere with controlled humidity. The nature of their conductivity is mixed ionic-hole. The conductivity value of the BaNd2O4 composition is higher than that of the BaSm2O4 composition. The greatest values of the ionic conductivity were recorded for the BaSm2O4 composition, in which the share of oxygen ionic transport reaches up to 85% at low temperatures. The values of electrical conductivity at 700 oC are –3.2 and –3.6 S/cm for the BaNd2O4 and BaSm2O4 compositions; the values of ionic conductivity are –3.7 and –4.2 S/cm, correspondingly.

Complex oxides with a spinel structure can be considered as promising electrolyte materials for electrochemical devices to be used in energy generation. In this paper, complex oxides with a spinel structure were obtained, and their electrical conductivity properties at various pH2O and pO2 were investigated for the first time. These compositions are unstable in a humid atmosphere and decompose to barium hydroxide and metal oxide. The electrical conductivity values of BaNd2O4 and BaSm2O4 spinels must be measured strictly in an atmosphere with controlled humidity. The nature of their conductivity is mixed ionic-hole. The conductivity value of the BaNd2O4 composition is higher than that of the BaSm2O4 composition. The greatest values of the ionic conductivity were recorded for the BaSm2O4 composition, in which the share of oxygen ionic transport reaches up to 85% at low temperatures. The values of electrical conductivity at 700 oC are –3.2 and –3.6 S/cm for the BaNd2O4 and BaSm2O4 compositions; the values of ionic conductivity are –3.7 and –4.2 S/cm, correspondingly.

Co-doped LaInO3-based materials have been studied. Strontium-sustituted solid solutions have high conductivity values but exhibit a low level of oxygen deficiency. Mg2+ and Ca2+ ions have been selected as the B-sublattice co-dopant. Both series of the solid solutions—La0.9Sr0.1In1 – xCaxO2.95 – 0.5x and La0.9Sr0.1In1 – yMgyO2.95 – 0.5y—crystallize in orthorhombic symmetry with space group Pnma. Ionic conductivity in a dry atmosphere is determined by the transport of oxygen ions. Oxygen-ion transport in solid solutions is 30–40

The search for new promising ceramic materials for various applications is an important task. In particular, ceramic materials are required as a part of electrochemical energy devices such as solid oxide fuel cells. Layered perovskites are promising materials for proton-conducting electrolyte of solid oxide fuel cells. In this article, samarium doped composition BaLa0.9Sm0.1InO4 was obtained for the first time. The effect of doping on the structure, water uptake and ionic transport (O2– and H+) was investigated. It was shown that the samarium doping leads to the increase in conductivity values of up to 2 orders of magnitude. At low temperatures the proton transport numbers are 87 – 93%, which indicates dominance of proton transfer.

This paper is devoted to the study of LaInO3 based co-doped materials. Solid solutions in which lanthanum is substituted for strontium have sufficiently high conductivity values, but a low level of oxygen deficiency is realized. Mg2+ and Ca2+ ions were chosen as co-dopants for the B sublattice. Both series of the investigated La0.9Sr0.1In1-xCaxO2.95–0.5x and La0.9Sr0.1In1-yMgyO2.95-0.5y solid solutions crystallize in orthorhombic symmetry with sp. gr. Pnma. The ionic conductivity in a dry atmosphere is determined by the oxygen ions transport. Oxygen-ion transfer in solid solutions is ~30–40% at high temperatures (T 700°C) and increases to 80% as the temperature decreases to 400–300°C. The substitution Ca2+ with In3+ increases the electrical conductivity of the oxygen ions; the highest values are achieved for the compositions La0.9Sr0.1In0.95Ca0.05O2.925 and La0.9Sr0.1In0.9Ca0.1O2.9. The introduction of Mg2+ co-dopant at the In3+ positions leads to a decrease in ionic conductivity compared to La0.9Sr0.1InO2.95. The effects of changing oxygen mobility with changing geometric factors (cell volume, critical radius) are discussed.

Perovskite or perovskite-related structural materials are widely studied for their many functional properties. They can be used as components of electrochemical devices such as solid oxide fuel cells and electrolyzers. Layered perovskites can also be considered as promising materials for use in these devices. In this paper, the possibility of heterovalent (acceptor and donor) and isovalent doping of La and In sublattices of layered perovskites BaYLaInO4 and BaGdLaInO4 was made for the first time. The structure and electrical properties of these oxides were studied. Electrical conductivity values increase in the series BaYInO4–BaLaInO4–BaGdInO4. However, the doping is an unsuitable strategy for improving the electrical properties of BaYInO4 and BaGdInO4 oxides. Further search for highly conductive materials with the layered perovskite structure can be aimed at materials with a different composition of the cation sublattice.

Materials engineering is an important trajectory for the design of new complex oxide compounds for their high-temperature application in solid oxide electrochemical cells. Usually, tailoring the functional properties of such compounds is realized through a cationic-type doping strategy, when a partial substitution of basic cations with impurity ions is performed. Typically, such a doping improves some properties, but deteriorates others due to significant changes in the cationic framework of a crystal. Anionic-type doping is an alternative way to leave the cationic sites unchanged, which may be suitable for achieving a compromise between a variety of properties. In this brief review, we summarize the existing data devoted to the F-doping (or F-insertion) of solid oxide electrolyte and electrode materials. In most cases, the F-doping improves the chemical stability of compounds and their ionic transport properties. Possible reasons responsible for this improvement are briefly discussed. In addition to highlighting these advantages, possible drawbacks are also listed to stimulate further research activities on this problem.

The search for novel functional ceramic materials with targeted properties is currently very important. Complex oxides with perovskite or perovskite-related structure are being considered for the production of electrochemical devices for the hydrogen energy ecosystem. Layered perovskites including based on BaLaInO4 4 are promising materials for proton-conducting electrolyte of solid oxide fuel cells. The idea of this work is to create a triple conductivity material based on BaLaInO4. 4 . In this work, the doping of the lanthanum sublattice with iron ions was carried out for the first time. The effect of doping on the structure, water uptake and electrical conductivity was investigated. It was shown that the introduction of iron ions into lanthanum sublattice changes the crystal lattice from orthorhombic to tetragonal structure. The water uptake is very small and it is 0.02 mol H2O 2 O per formula unit for BaLa0.9Fe0.1InO4-delta 0.9 Fe 0.1 InO 4-delta composition. Studies of the electrical properties have shown that the nature of conductivity is mixed hole/oxygen ionic at dry air and hole/oxygen ionic/protonic and wet air. The Fe-doped- composition can be considered as triple conducting materials and it is prospective as the electrode materials comparable with protonic electrolyte Ba 1.1 La 0.9 InO 3.95 .

Hydrogen energy is one of the ways to ensure environmentally friendly and sustainable development of human society. Solid oxide fuel cells are designed to produce energy using hydrogen as fuel. One of the most important components of solid oxide fuel cells is the electrolyte. New promising electrolyte materials are compositions with Ruddlesden-Popper structure, in particular BaLa2In2O7. However, the mechanism of ionic transport has not been studied. In this paper, the electronic structure and chemical bonding were examined using a combination of experimental methods and theoretical calculations. This article is the first step towards understanding the nature of the ion transport mechanism in the composition BaLa2In2O7 with Ruddlesden-Popper structure.

Proton conducting materials are used in electrochemical devices such as proton conducting fuel cells and proton conducting electrolyzers. These devices belong to the hydrogen energy field and serve the goals of clean energy and sustainable environmental development. Layered perovskites are a promising class of proton conducting electrolytes. Cationic co-doping is a well-known method to improve the transport properties of classical perovskite ABO3. However, data on the application of this method to layered perovskites are limited. In this work, the bilayered perovskites BaLa1.9−xSrxGd0.1In2O7−0.5x have been prepared and studied for the first time. The possibility of oxygen-ionic and proton transport was demonstrated. Cationic co-doping was shown to increase the proton conductivity values by up to 1.5 orders of magnitude.

Proton-conducting electrochemical devices such as protonic ceramic fuel cells and protonic ceramic electrolysis cells play a major role in the creation of eco-friendly "green" energy systems. The most studies of proton-conducting materials for these devices are barium cerate zirconates. The layered perovskites are novel class of proton-conducting materials. In this paper, the possibility of cation and oxyanion doping of layered perovskite BaNd2In2O7 was carried out for the first time. The most conductive composition BaLa1.9Sr0.1In2O6.95 demonstrates protonic conductivity value 2$10-5 S/cm at 450 & DEG;C. The acceptor-doped two-layer perovskites are the prospective class of proton-conducting materials, and further modification of their composition opens up a new way in the design of solid oxide protonic conductors. & COPY; 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Creation of new ceramic materials for the bone augmentation purposes that combine the absence of cytotoxicity, high strength and osseointegration characteristics is an urgent modern task. In this work, the cytocompatibility of ceramic materials based on lanthanum zirconate (La2Zr2O7) was determined to assess the prospects for their use as implants and components of human joint endoprostheses. The effect of ceramic materials based on undoped and alkali-earth (Ca, Sr) doped La2Zr2O7 on the viability and proliferative activity of human cells was evaluated. The release of elements into the culture medium was also evaluated.

Министерство науки и высшего образования Российской Федерации Российское химическое общество им.Д.И.Менделеева Секция по химической термодинамике и термохимии Научного совета РАН по физической химии Сибирское Отделение Российской Академии Наук Институт неорганической химии им.А.В.Николаева СО РАН

Active development of electrochemical devices such as proton-conducting fuel cells and electrolyzers should ensure sustainable environmental development. An electrolyte material of a hydrogen-powered electrochemical device must satisfy a number of requirements, including high proton conductivity. Layered perovskites are a promising class of proton-conducting electrolytes. The cationic co-doping method has been successfully applied to well-known proton conductors with the classical perovskite structure ABO3. However, the data on the application of this method to layered perovskites are limited. In this work, the bilayer perovskites BaLa1.9Sr0.1In1.95M0.05O6.925 (M = Mg2+, Ca2+) were obtained and investigated for the first time. Cationic co-doping increases oxygen-ion and proton conductivity values.

This work represents research into materials designed to improve the environment. The study was carried out on aluminum hydroxide xerogels and alumina catalysts obtained by the Controlled Double Jet Precipitation (CDJP) process at different pH values. It has been shown that the pH of the CDJP process determines the content of aluminum-bound nitrate ions in the aluminum hydroxide. These ions are removed at a higher temperature than the decomposition of ammonium nitrate. The high content of aluminum-bound nitrate ions determines the structural disorder of the alumina and the high content of the penta-coordinated alumina catalyst.

One of the urgent tasks of applied materials science is the creation of novel high-effective materials with target properties. In the area of energy systems, there is a problem in the conversion of chemical energy to electricity without mechanical work. Hydrogen energy provides a way using electrochemical devices such as protonic ceramic fuel cells. Novel advanced proton-conducting materials with the top characteristics of target properties are strictly needed. Layered perovskites are a novel and promising class of protonic conductors. In this work, the layered perovskite BaLa0.9Pr0.1InO4 was obtained and investigated as a protonic conductor for the first time. The possibility for water intercalation and proton transport is proved. It was shown that isovalent doping Pr3+ → La3+ leads to an increase in the crystal lattice size, proton concentration and proton mobility. The proton conductivity value for doped BaLa0.9Pr0.1InO4 composition is 18 times greater than for undoped BaLaInO4 composition. Layered perovskites based on BaLaInO4 are promising materials for application in proton-conducting electrochemical devices.

The effect of Ca2+ − doping on the electrical conductivity of the oxide BaLa2In2O7 with Ruddlesden-Popper structure was investigated for the first time. The BaCaxLa2-xIn2O7-0.5× solid solution exists in the composition range of 0 ≤ x ≤ 0.10. The electrical conductivity of the BaCaxLa2-xIn2O7-0.5× ceramic samples was measured as a function of temperature (T), oxygen partial pressure (pO2), and water vapor partial pressure (pH2O). The introduction of Ca2+ into the crystal lattice led to an increase in oxygen-ion conductivity by 0.25 orders of magnitude at 500 °C, which is attributed to the formation of oxygen vacancies. The share of oxygen-ion transport increased from 23 to 80

The paper discusses the features of proton transport in isovalently doped layered perovskites based on barium-lanthanum indate BaLaInO4. The effect of the nature and concentration of the dopant on the unit cell size, water absorption, and proton conductivity was estimated. It is shown that the doping of the cationic sublattices of the layered perovskite BaLaInO4 with Nd3+, Gd3+, Pr3+, In3+, Y3+ ions makes it possible to increase the proton conductivity up to ~ 2 orders of magnitude, and the complex oxides obtained by this method are promising from the point of view of their further study as a material for a proton-conducting solid oxide electrolyte fuel cell.

Hydrogen energy is one of the most developing areas of clean energy due to various ad-vantages of hydrogen compared to traditional fossil fuels. One of hydrogen energy elec-trochemical devices is proton-conducting solid oxide fuel cells. The obtaining of novel highly proton conductive materials is relevant. Nonmetal doping strategy to improve the protonic conductivity in perovskite-related materials is understudied. The phosphorous-doped perovskite CaZr0.95P0.05O3.025 was obtained for the first time. The possibility for water uptake was proved by thermogravimetry and mass-spectrometry investigations. It was shown that phosphorous doping led to increase in the conductivity values up to 500 times. The composition CaZr0.95P0.05O3.025 demonstrates nearly pure proton transport below 600 & DEG;C under wet air. The proton conductivity values are 3.3.10-6 S/cm at 670 & DEG;C and 7.6.10-7.S/cm at 500 & DEG;C. The nonmetal doping strategy is prospective way to enhance electrical conductivity of proton conductors with perovskite structure.

— The oxygen-ionic conductivity of isovalent-doped complex oxides characterized by the Ruddlesden–Popper structure is studied. The BaLa 0.9 Nd 0.1 InO 4 sample was obtained for the first time by substitution in the La sublattice, and its transport properties are studied. A comparing of the results with the data for samples obtained earlier by isovalent substitution in the In-sublattice of BaLaInO 4 is presented. The introducing of a dopant is shown to lead to increase in the contribution from oxygen-ionic conductivity and also in the total conductivity by ~2 orders of magnitude.