Progress in Solid State Chemistry最新文献

Today, carbon dioxide (CO₂) is one of the most pervasive greenhouse gases in the atmosphere, mainly because of the burning of fossil fuels. The carbon dioxide reduction reaction by photocatalysis and electrocatalysis is one approach that holds a lot of promise for easing the global crisis on the environmental and energy fronts. Developing and constructing high-performance photo- and electrocatalysts is a challenge that is being studied. The class of anionic metal-oxo clusters known as polyoxometalates (POMs) brings diverse and interesting chemical and physical characteristics that can be modified easily. The studies reveal that POMs are emerging to be distinctive photo/electrocatalysts for these reactions because of their unmatched advantages, like thermal and redox stability, light-absorbing capacity, quasi-semiconductor properties, etc. Numerous studies have demonstrated the capability of tungsten and molybdenum-based photo- and electrocatalysts for CO₂ reduction and conversion into value-added products. This review has covered the most recent developments in tungsten and molybdenum-based POMs that convert CO₂ into multiple products (CO, H₂, HCOOH, HCHO, CH₃OH, etc.). Perspectives for designing and constructing different kinds of POM-based catalytic systems have been offered.

This comprehensive review paper offers an extensive overview of recent developments in doping strategies to enhance the applications of M-type hexaferrites. These distinctive materials have gained considerable attention across a range of technological fields. The paper focuses on structural attributes of M-type hexaferrites, delves into their diverse applications—such as permanent magnets, high-density storage media, EMI shielding, photocatalysis for wastewater treatment, and potential for hydrogen storage—and underscores their suitability for these uses. The review also investigates the influence of doping on the performance of M-type hexaferrites in various applications. The insights presented herein not only provide a deeper understanding of the potential of M-type hexaferrites but also pave the way for future advancements in this dynamic field.

CuAl₂-type VN₂, which is synthesized under high pressure, is a recoverable material at ambient conditions and has a high bulk modulus. In this study, we investigated the thermal expansion behavior of CuAl₂-type VN₂ by low-temperature X-ray diffraction measurements between 109.3(5) K and 298.3(8) K. The axial thermal expansion coefficient of VN₂ was determined to be α_a = 2.7(9) × 10⁻⁶ K⁻¹ and α_c = 17.8(12) × 10⁻⁶ K⁻¹ at 298.3(8) K, which has large anisotropy similar to that of compression behavior. It is found that the small coefficient of thermal expansion of the a-axis is due to the negative and positive effects on the a-axis length with increasing temperature of the bond angles and bond lengths of VN₂, respectively. As a result, VN₂ exhibits very large anisotropic thermal expansion behavior.

Double perovskites R₂NiMnO₆ (R = Rare earth element) (RNMO) are a significant class of materials owing to their Multifunctional properties with the structural modifications. In particular, multifunctional double perovskite oxides La₂NiMnO₆ (LNMO) which possess both electric and magnetic orderings, chemical flexibility, versatility, and indispensable properties like high ferromagnetic curie temperature, high absorption rates, dielectrics, etc. have drawn a lot of attention due their rich physics and diverse applications in various technology. This justifies the intense research in this class of materials, and the keen interest they are subject to both the fundamental and practical side. In view of the demands of this material in lead-free perovskite solar cells, photocatalytic degradation of organic dyes, clean hydrogen production, electric tuneable devices, fuel cells, gas sensing, and biomedical applications, there is a need for an overview of all the literature so far, the ongoing research and the future prospective. This review summarised all the physical and structural properties of LNMO such as electric, magnetic, catalytic, and dielectric properties with their underlying mechanisms. This review article provides insight into the scope of studies in LNMO material for exploring unexposed properties in new material research and to identify areas of future investigation of the materials in the double perovskite family.

Due to ultralow defect formation energy, borophene differs significantly from other 2D (two-dimensional) materials in that it is difficult to distinguish between its crystal and boron (B) vacancy defect. In contrast to other 2D materials like graphene, borophene does not form layers when it is in its bulk state. In addition, borophene NM's atomic structure is different from graphene's in that it consists of connected triangles rather than hexagons. This atomic configuration has gaps where atoms are missing, resulting in a flaw called a "hollow hexagon" (HH). In borophene phases, these HHs can be found in a variety of ratios. The phase intermixing of borophene is a brand-new example of an 'ordered' defect discovered in 2D materials.

The majority of 2D materials have flaws or disruptions to the atom arrangement at the boundaries between various domains or phases. Defects play a major influence in determining the properties of materials in a 2D system, because all atoms are virtually on the surface. For instance, the line defects along phase boundaries in borophene have no effect on the material's electrical characteristics at ambient temperature, in contrast to insulating flaws in metallic graphene. The atoms at the borders of borophene easily fit along line faults and adopt the configuration of their neighbors, causing no disruption. Additionally, the line flaws do not disrupt the seamless structure of borophene and maintain its stability and metallic properties.

Experimentally, all four borophene phases have been synthesized, and they are all metallic. A list of borophene NM's special characteristics, including its negative Poisson's ratio and extremely anisotropic Young's modulus, is discussed. Here we also emphasized on B's conductive and superconductive qualities. An overview of borophene NM's uses in the energy sectors, including metal ion batteries, and supercapacitors (SCs), is covered in great length at the very end.

In this paper, we investigate the structure and thermal properties of aluminum-rich transparent Ca–Al–Si–O–N glasses. The obtained glasses were prepared by a traditional melt-quenching technique at 1650 °C using AlN as the nitrogen source. The obtained glasses have a n_Al/n_Si>1 and contain up to 17 eq.% of N. The structure of the glasses was characterized by X-ray diffraction, X-ray photoelectron spectroscopy, infrared, and Raman spectroscopy techniques. The structure analysis shows a higher preference for Si–N bond formation relative to Al–N bond formation and aluminum is predominately present in tetrahedral coordination as AlO₄ units. The thermal properties of samples were studied by differential thermal analysis and the obtained glass transition temperature ranges from 875 °C to 950 °C, and is primarily influenced by the N content. The glass stability can be correlated with both the N and Al contents in the studied glasses. It is improved due to the increased degree of network polymerization by the incorporation of nitrogen.

Stable tetragonal C₉ and C₁₂ with original topologies have been devised based on crystal chemistry rationale and unconstrained geometry optimization calculations within the density functional theory (DFT). The two new carbon allotropes characterized by corner- and edge-sharing tetrahedra, are mechanically (elastic constants) and dynamically (phonons) stable and exhibit thermal and mechanical properties close to diamond. The electronic band structures show insulating behavior with band gaps close to 5 eV, like diamond.

The vast range of uses that Z-type hexaferrite nanoparticles (ZTHNPs) offer in a variety of fields, including antennas, microwave absorption, and biomedicine has sparked a lot of scientific interest in these nanoparticles. Z-type hexaferrite possesses a soft magnetic character, planar magneto-crystalline anisotropy, and acceptable ultra-high frequency electromagnetic characteristics. The major topics of this review paper are the crystal structure, synthesis strategies (sol-gel, co-precipitation, solid-state reaction, hydrothermal techniques), characteristics, and prospective uses of Z-type hexaferrite, with a special emphasis on recently published research. Firstly, the crystal structure and most prominent synthesis strategies of ZTHNPs, with their benefits and drawbacks, are described. Secondly, we focused more of our attention on the magnetic, structural, and electromagnetic behaviours of this material. The final section discusses the prospective applications of these novel multifunctional materials.

Double perovskites R₂NiMnO₆ (R = Rare earth element) (RNMO) are a significant class of materials owing to their varied tunability of the magnetic and electrical properties with the structural modifications. Pr₂NiMnO₆ (PNMO) is one of the least explored members of this series, which shows spin-phonon coupling, magnetocaloric effect and electrochemical performance for various applications such as spintronics, magnetocaloric refrigerant and solid oxide fuel cells. Most of the studies in PNMO are limited to the application domain and focus on the comparative study with different rare earth elements. Detailed structural studies like neutron diffraction are sparse in PNMO samples which will give a perception of the A/B-site cationic (Pr/Ni/Mn-site cationic) ordering in the compound that strongly depends on the physical and chemical properties. This review article goes through the various aspects of PNMO materials that have been reported till now and showcases the octahedral distortions and corresponding structural changes and the exchange interactions, which in turn correlate with the magnetic and electrical properties. The comparison study of PNMO with other members of the RNMO (R = Rare earth) family and the relevance of PNMO over other members is also tried to showcase in this article. This review article provides insight into the scope of studies in PNMO material for exploring unexposed properties of the materials in the double perovskite family.

Alkali-rich layered oxides Li₂SnO₃ and Na₂SnO₃ are isostructural, but no alkali-mixed compositions have been reported so far. While the thermodynamic stability of such mixed compositions is predicted by DFT calculations mainly for the sodium-rich side, single-phase compounds Li_2-xNa_xSnO₃ were successfully obtained in the whole composition range (0 ≤ x ≤ 2) by conventional solid-state synthesis thanks to a quenching procedure at the end of the heat treatment. From Li₂SnO₃ to Na₂SnO₂, the evolution of the cell parameters and the DFT calculations demonstrate that the lithium-to-sodium substitution occurs firstly inside the alkali layer up to Li_0.5Na_1.5SnO₃ and then in the honeycomb layer.