scholarly journals Complex Catalytic Materials Based on the Perovskite-Type Structure for Energy and Environmental Applications

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5555
Author(s):  
Florin Andrei ◽  
Rodica Zăvoianu ◽  
Ioan-Cezar Marcu
Keyword(s):  
Energy Production ◽  
Review Paper ◽  
Preparation Method ◽  
Methane Combustion ◽  
Environmental Applications ◽  
Waste Waters ◽  
Short Introduction ◽  
Catalytic Applications ◽  
Perovskite Type ◽  
Perovskite Type Structure

This review paper focuses on perovskite-type materials as (photo)catalysts for energy and environmental applications. After a short introduction and the description of the structure of inorganic and hybrid organic-inorganic perovskites, the methods of preparation of inorganic perovskites both as powders via chemical routes and as thin films via laser-based techniques are tackled with, for the first, an analysis of the influence of the preparation method on the specific surface area of the material obtained. Then, the (photo)catalytic applications of the perovskites in energy production either in the form of hydrogen via water photodecomposition or by methane combustion, and in the removal of organic pollutants from waste waters, are reviewed.

Optical Spectra, EPR, and Spin–Lattice Relaxation of Yb3+ Ions in Crystals Having Perovskite-Type Structure

1977 ◽  
Vol 81 (1) ◽  
pp. 287-293 ◽  
Author(s):  
A. A. Antipin ◽  
A. V. Vinokurov ◽  
M. P. Davydova ◽  
S. L. Korableva ◽  
A. L. Stolov ◽  
...  
Keyword(s):  
Lattice Relaxation ◽  
Optical Spectra ◽  
Type Structure ◽  
Spin Lattice Relaxation ◽  
Spin Lattice ◽  
Perovskite Type ◽  
Perovskite Type Structure

A Review of Advances in Multifunctional XTiO3 Perovskite-type Oxides as piezo-photocatalysts for Environmental Remediation and Energy Production

2021 ◽  
pp. 126792
Author(s):  
Ridha Djellabi ◽  
Marcela Frias Ordonez ◽  
Francesco Conte ◽  
Ermelinda Falletta ◽  
Claudia L. Bianchi ◽  
...  
Keyword(s):  
Environmental Remediation ◽  
Energy Production ◽  
Perovskite Type

scholarly journals Crystal structures of isotypic poly[bis(benzimidazolium) [tetra-μ-iodido-stannate(II)]] and poly[bis(5,6-difluorobenzimidazolium) [tetra-μ-iodido-stannate(II)]]

2014 ◽  
Vol 70 (10) ◽  
pp. 178-182 ◽  
Author(s):  
Iwan Zimmermann ◽  
Tony D. Keene ◽  
Jürg Hauser ◽  
Silvio Decurtins ◽  
Shi-Xia Liu
Keyword(s):  
Hydrogen Bonds ◽  
Point Group ◽  
Van Der Waals Interactions ◽  
Group Symmetry ◽  
Layered Perovskite ◽  
Out Of Plane ◽  
Related Compounds ◽  
Perovskite Type ◽  
Inorganic Layers ◽  
Perovskite Type Structure

The isostructural title compounds, {(C7H7N2)2[SnI4]}n, (1), and {(C7H5F2N2)2[SnI4]}n, (2), show a layered perovskite-type structure composed of anionic {[SnI4]2−}nsheets parallel to (100), which are decorated on both sides with templating benzimidazolium or 5,6-difluorobenzimidazolium cations, respectively. These planar organic heterocycles mainly form N—H...I hydrogen bonds to the terminal I atoms of the corner-sharing [SnI6] octahedra (point group symmetry 2) from the inorganic layer, but not to the bridging ones. This is in contrast to most of the reported structures of related compounds where ammonium cations are involved. Here hydrogen bonding to both types of iodine atoms and thereby a distortion of the inorganic layers to various extents is observed. For (1) and (2), all Sn—I—Sn angles are linear and no out-of-plane distortions of the inorganic layers occur, a fact of relevance in view of the material properties. The arrangement of the aromatic cations is mainly determined through the direction of the N—H...I hydrogen bonds. The coherence between organic bilayers along [100] is mainly achieved through van der Waals interactions.

Pb-DOPING EFFECTS ON THE DIELECTRIC AND PYROELECTRIC PROPERTIES OF (Sr,Pb)TiO3 SYSTEM

2012 ◽  
Vol 02 (01) ◽  
pp. 1250005 ◽  
Author(s):  
Y. P. JIANG ◽  
X. G. TANG ◽  
Y. C. ZHOU ◽  
Q. X. LIU
Keyword(s):  
Dielectric Permittivity ◽  
Frequency Dispersion ◽  
X Ray Diffraction ◽  
Pyroelectric Properties ◽  
Doping Effects ◽  
Pyroelectric Sensors ◽  
Diffraction Patterns ◽  
Perovskite Type ◽  
Pb Doping ◽  
Perovskite Type Structure

Lead strontium titanate ( Sr 1-x Pb x) TiO 3 (0.20 ≤ x ≤ 0.45,step = 0.05) ceramics were prepared by conventional mixed oxide method. The X-ray diffraction patterns indicate that the prepared samples have perovskite-type structure. With the increase of Pb content, there is a tendency from the cubic to tetragonal structure. The scanning electron microscopy micrographs reveal that the addition of Pb can affect microstructure. The dependent temperature dielectric permittivity and dielectric loss were investigated in the frequency range from 100 Hz to 1 MHz. The maximum peak of the dielectric permittivity versus temperature curve was broadened and a frequency dispersion of the dielectric permittivity was observed for the (Sr0.8Pb0.2)TiO3 ceramics. The results obtained at the frequency of 10 kHz reveal the Curie temperature linearly increased with the lead content. The fitted curves of temperature versus inverse dielectric permittivity at 10 kHz for ( Sr 1-x Pb x) TiO3 ceramics are consistent with Curie–Weiss law. The Pyroelectric properties were also investigated. The high pyroelectric coefficients and figure of merits indicate that the SPT ceramics are potential materials for pyroelectric sensors.

Structures of CsEuBr3 and its degradation product Cs2EuBr5·10H2O

2007 ◽  
Vol 63 (2) ◽  
pp. 201-204 ◽  
Author(s):  
Helmut Ehrenberg ◽  
Hartmut Fuess ◽  
Sabine Hesse ◽  
Jörg Zimmermann ◽  
Heinz von Seggern ◽  
...  
Keyword(s):  
Degradation Products ◽  
Water Molecules ◽  
X Ray ◽  
Synchrotron Powder Diffraction ◽  
Prepared Material ◽  
Octahedral Tilting ◽  
Perovskite Type ◽  
Perovskite Type Structure ◽  
The Eu ◽  
Degraded Product

CsEuBr3, caesium europium tribromide, crystallizes in an orthorhombic perovskite-type structure with an a − a − c + octahedral tilting scheme (GdFeO3 type). CsEuBr3 is unstable in air and one of the degradation products was identified as Cs2EuBr5·10H2O by single-crystal X-ray analysis and synchrotron powder diffraction. The Eu3+ ions on twofold rotational axes are coordinated by nine water molecules, and each water O atom is linked to two Br atoms by hydrogen bonds. The tricapped trigonal [EuO9] prisms are separated from each other by infinite {Cs2Br5·H2O} chains; the description Eu(OH2)9Cs2Br5(OH2) might therefore be more appropriate. The oxidation of Eu2+ to Eu3+ during the degradation of CsEuBr3 is further confirmed by changes in the magnetic properties from the as-prepared material into the degraded product.

Thermoelectric Oxides and Oxynitrides with Perovskite-type Structure

2007 ◽  
Vol 1044 ◽  
Author(s):  
Anke Weidenkaff ◽  
Laura Bocher ◽  
Rosa Robert ◽  
Myriam Aguirre ◽  
Dmitry Logvinovich
Keyword(s):  
Transition Metal Oxides ◽  
Lattice Thermal Conductivity ◽  
Complex Oxide ◽  
Type Structure ◽  
Soft Chemistry ◽  
Large Power ◽  
Thermoelectric Oxides ◽  
Synthesis Routes ◽  
Perovskite Type ◽  
Perovskite Type Structure

AbstractTransition metal oxides and oxynitrides with perovskite-type structures are potential high temperature stable thermoelectric materials. With innovative soft chemistry synthesis procedures the crystallite size in complex oxide ceramics with perovskite-type structure can be decreased compared to classical synthesis routes and allows to lower the heat conductivity dramatically while a large power factor can be maintained at the same time. Submicron crystallites are beneficial to lower the lattice thermal conductivity without influencing the electron mobility.In this work, perovskite-type cobaltates, molybdates and manganates are studied. The influence of heterostructures and nanocrystalline domains in perovskite oxides/oxynitrides and the correlation with transport properties and Seebeck coefficient will be discussed.

Studies of Distortion in Potassium Manganese Fluoride, KMnF3, at 10°K: an Example of Powder Profile Analysis Using the Pearson Type VII Distribution

1990 ◽  
Vol 5 (1) ◽  
pp. 41-43 ◽  
Author(s):  
A. Ratuszna ◽  
K. Majewska
Keyword(s):  
Profile Analysis ◽  
Electronic System ◽  
Maximum Intensity ◽  
Automatic Data ◽  
X Ray ◽  
Distorted Structure ◽  
Pearson Type Vii Distribution ◽  
Pearson Type ◽  
Perovskite Type ◽  
Perovskite Type Structure

AbstractPearson VII functions, some of the most useful descriptions of the intensity distribution within the X-ray powder reflection, have been used to study distortion in the perovskite-type structure of KMnF3. Separate full-widths, Δ, at half-maximum intensity, and Pearson exponents, m, were taken for the low- and high-angle sides of the profiles. The background was assumed to be linear. For the distorted structure, summation was made over all overlapping lines that might possibly contribute to the observed profile. Measurements were performed using a powder diffractometer with a specially adapted electronic system consisting of an automatic data recorder and a method, developed at this laboratory, for transferring data to an IBM PC/AT computer. By these means it could be shown that at 10° K the crystal structure of KMnF3distorts from cubic to monoclinic.

scholarly journals Major Advances and Challenges in Heterogeneous Catalysis for Environmental Applications: A Review

2018 ◽  
Vol 25 (1) ◽  
pp. 9-34 ◽  
Author(s):  
Stanisław Wacławek ◽  
Vinod V.T. Padil ◽  
Miroslav Černík
Keyword(s):  
Heterogeneous Catalysis ◽  
Sustainable Energy ◽  
Soil Treatment ◽  
Environmental Applications ◽  
Environmental Sciences ◽  
Short Introduction ◽  
New Developments ◽  
Historical Aspects ◽  
Small Section ◽  
Strongly Connected

Abstract Heterogeneous catalysis is one of the fastest developing branches of chemistry. Moreover, it is strongly connected to popular environment-related applications. Owing to the very fast changes in this field, for example, numerous discoveries in nanoscience and nanotechnologies, it is believed that an update of the literature on heterogeneous catalysis could be beneficial. This review not only covers the new developments of heterogeneous catalysis in environmental sciences but also touches its historical aspects. A short introduction to the mechanism of heterogeneous catalysis with a small section on advances in this field has also been elaborated. In the first part, recent innovations in the field of catalytic air, water, wastewater and soil treatment are presented, whereas in the second part, innovations in the use of heterogeneous catalysis for obtaining sustainable energy and chemicals are discussed. Catalytic processes are ubiquitous in all branches of chemistry and there are still many unsolved issues concerning them.

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