Showing papers on "Phase (matter) published in 2020"
TL;DR: It is found that heterotypic interactions among protein and RNA components stabilize various archetypal intracellular condensates—including the nucleolus, Cajal bodies, stress granules and P-bodies—implying that the composition of condensate is finely tuned by the thermodynamics of the underlying biomolecular interaction network.
Abstract: Intracellular bodies such as nucleoli, Cajal bodies and various signalling assemblies represent membraneless organelles, or condensates, that form via liquid–liquid phase separation (LLPS)1,2. Biomolecular interactions—particularly homotypic interactions mediated by self-associating intrinsically disordered protein regions—are thought to underlie the thermodynamic driving forces for LLPS, forming condensates that can facilitate the assembly and processing of biochemically active complexes, such as ribosomal subunits within the nucleolus. Simplified model systems3–6 have led to the concept that a single fixed saturation concentration is a defining feature of endogenous LLPS7–9, and has been suggested as a mechanism for intracellular concentration buffering2,7,8,10. However, the assumption of a fixed saturation concentration remains largely untested within living cells, in which the richly multicomponent nature of condensates could complicate this simple picture. Here we show that heterotypic multicomponent interactions dominate endogenous LLPS, and give rise to nucleoli and other condensates that do not exhibit a fixed saturation concentration. As the concentration of individual components is varied, their partition coefficients change in a manner that can be used to determine the thermodynamic free energies that underlie LLPS. We find that heterotypic interactions among protein and RNA components stabilize various archetypal intracellular condensates—including the nucleolus, Cajal bodies, stress granules and P-bodies—implying that the composition of condensates is finely tuned by the thermodynamics of the underlying biomolecular interaction network. In the context of RNA-processing condensates such as the nucleolus, this manifests in the selective exclusion of fully assembled ribonucleoprotein complexes, providing a thermodynamic basis for vectorial ribosomal RNA flux out of the nucleolus. This methodology is conceptually straightforward and readily implemented, and can be broadly used to extract thermodynamic parameters from microscopy images. These approaches pave the way for a deeper understanding of the thermodynamics of multicomponent intracellular phase behaviour and its interplay with the nonequilibrium activity that is characteristic of endogenous condensates. Heterotypic multicomponent interactions are shown to dominate the liquid–liquid phase separation that enables the formation of intracellular condensates.
362 citations
TL;DR: This review comprehensively trace recent advances in understanding delicate interplay of strong and weak interactions that underpin their complex phase behaviors with a particular emphasis on understanding heterogeneous microstructures and dynamics of ILs in bulk liquids, in mixtures with cosolvents, and in interfacial regions.
Abstract: Ionic liquids (ILs) are a special category of molten salts solely composed of ions with varied molecular symmetry and charge delocalization. The versatility in combining varied cation-anion moieties and in functionalizing ions with different atoms and molecular groups contributes to their peculiar interactions ranging from weak isotropic associations to strong, specific, and anisotropic forces. A delicate interplay among intra- and intermolecular interactions facilitates the formation of heterogeneous microstructures and liquid morphologies, which further contributes to their striking dynamical properties. Microstructural and dynamical heterogeneities of ILs lead to their multifaceted properties described by an inherent designer feature, which makes ILs important candidates for novel solvents, electrolytes, and functional materials in academia and industrial applications. Due to a massive number of combinations of ion pairs with ion species having distinct molecular structures and IL mixtures containing varied molecular solvents, a comprehensive understanding of their hierarchical structural and dynamical quantities is of great significance for a rational selection of ILs with appropriate properties and thereafter advancing their macroscopic functionalities in applications. In this review, we comprehensively trace recent advances in understanding delicate interplay of strong and weak interactions that underpin their complex phase behaviors with a particular emphasis on understanding heterogeneous microstructures and dynamics of ILs in bulk liquids, in mixtures with cosolvents, and in interfacial regions.
236 citations
TL;DR: It is shown that doping leads not only to a decrease in the concentration of manganese in model solutions, but also to an increase in the efficiency of adsorption from 11% to 75%.
Abstract: The main purpose of this work is to study the effectiveness of using FeCeOx nanocomposites doped with Nb2O5 for the purification of aqueous solutions from manganese. X-ray diffraction, energy–dispersive analysis, scanning electron microscopy, vibrational magnetic spectroscopy, and mossbauer spectroscopy were used as research methods. It is shown that an increase in the dopant concentration leads to the transformation of the shape of nanoparticles from spherical to cubic and rhombic, followed by an increase in the size of the nanoparticles. The spherical shape of the nanoparticles is characteristic of a structure consisting of a mixture of two phases of hematite (Fe2O3) and cerium oxide CeO2. The cubic shape of nanoparticles is typical for spinel-type FeNbO4 structures, the phase contribution of which increases with increasing dopant concentration. It is shown that doping leads not only to a decrease in the concentration of manganese in model solutions, but also to an increase in the efficiency of adsorption from 11% to 75%.
211 citations
TL;DR: 3D stacking fault networks formation is image and it is shown they both impede dislocations and facilitate phase transformations via local chemical composition variations, which facilitate the construction of the stacking-fault networks to provide nucleation sites for the hcp phase transformation.
Abstract: Strategies involving metastable phases have been the basis of the design of numerous alloys, yet research on metastable high-entropy alloys is still in its infancy. In dual-phase high-entropy alloys, the combination of local chemical environments and loading-induced crystal structure changes suggests a relationship between deformation mechanisms and chemical atomic distribution, which we examine in here in a Cantor-like Cr20Mn6Fe34Co34Ni6 alloy, comprising both face-centered cubic (fcc) and hexagonal closed packed (hcp) phases. We observe that partial dislocation activities result in stable three-dimensional stacking-fault networks. Additionally, the fraction of the stronger hcp phase progressively increases during plastic deformation by forming at the stacking-fault network boundaries in the fcc phase, serving as the major source of strain hardening. In this context, variations in local chemical composition promote a high density of Lomer-Cottrell locks, which facilitate the construction of the stacking-fault networks to provide nucleation sites for the hcp phase transformation.
184 citations
TL;DR: It is shown that the photocatalytic activities and energy conversion efficiency can be well tuned by ferroelectric-paraelectric phase transition of AgBiP2Se6 monolayer, and the importance of ferro electric polarization on water splitting is revealed.
Abstract: Photocatalytic water splitting is a promising technology to solve the energy crisis and provide renewable and clean energies. Recently, although numerous 2D materials have been proposed as the photocatalytic candidates, the strategies to effectively modulate photocatalytic reactions and conversion efficiency are still lacking. Herein, based on first-principles calculations, we show that the photocatalytic activities and energy conversion efficiency can be well tuned by ferroelectric-paraelectric phase transition of a AgBiP2Se6 monolayer. It is found that the AgBiP2Se6 monolayer has a higher potential and driving forces of photogenerated holes for water oxidation in the ferroelectric phase, but higher corresponding values of photogenerated electrons for the hydrogen reduction reaction in the paraelectric phase. Besides, the solar-to-hydrogen energy conversion efficiency is also tunable with the phase transition; it is up to 10.04% at the ferroelectric phase due to the better carrier utilization, but only 6.66% at the paraelectric phase. Moreover, the exciton binding energy is always smaller in the paraelectric state than that in the ferroelectric state, indicating that the ferroelectric switch could also make a directional adjustment to the photoexcited carrier separation. Our theoretical investigation not only reveals the importance of ferroelectric polarization on water splitting, but also opens an avenue to modify the photocatalytic properties of 2D ferroelectric materials via a ferroelectric switch.
176 citations
TL;DR: In this article, the authors studied a layered compound, LaTe3, where a small lattice anisotropy in the a-c plane results in a unidirectional charge density wave (CDW) along the c axis1,2.
Abstract: When electrons in a solid are excited by light, they can alter the free energy landscape and access phases of matter that are out of reach in thermal equilibrium. This accessibility becomes important in the presence of phase competition, when one state of matter is preferred over another by only a small energy scale that, in principle, is surmountable by the excitation. Here, we study a layered compound, LaTe3, where a small lattice anisotropy in the a–c plane results in a unidirectional charge density wave (CDW) along the c axis1,2. Using ultrafast electron diffraction, we find that, after photoexcitation, the CDW along the c axis is weakened and a different competing CDW along the a axis subsequently emerges. The timescales characterizing the relaxation of this new CDW and the reestablishment of the original CDW are nearly identical, which points towards a strong competition between the two orders. The new density wave represents a transient non-equilibrium phase of matter with no equilibrium counterpart, and this study thus provides a framework for discovering similar states of matter that are ‘trapped’ under equilibrium conditions. Short pulses of light shift the balance between two competing charge density wave phases, allowing the weaker one to manifest transiently while suppressing the stronger one. This shows that competing phases can be tuned in a non-equilibrium setting.
146 citations
143 citations
TL;DR: The experimental determination of the structure and response to applied electric field of the lower-temperature nematic phase of the previously reported calamitic compound 4-[(4-nitrophenoxy)carbonyl]phenyl2,4-dimethoxybenzoate and results indicate a significant potential for transformative, new nematic physics, chemistry, and applications based on the enhanced understanding, development, and exploitation of molecular electrostatic interaction.
Abstract: We report the experimental determination of the structure and response to applied electric field of the lower-temperature nematic phase of the previously reported calamitic compound 4-[(4-nitrophenoxy)carbonyl]phenyl2,4-dimethoxybenzoate (RM734). We exploit its electro-optics to visualize the appearance, in the absence of applied field, of a permanent electric polarization density, manifested as a spontaneously broken symmetry in distinct domains of opposite polar orientation. Polarization reversal is mediated by field-induced domain wall movement, making this phase ferroelectric, a 3D uniaxial nematic having a spontaneous, reorientable polarization locally parallel to the director. This polarization density saturates at a low temperature value of ∼6 µC/cm2, the largest ever measured for a fluid or glassy material. This polarization is comparable to that of solid state ferroelectrics and is close to the average value obtained by assuming perfect, polar alignment of molecular dipoles in the nematic. We find a host of spectacular optical and hydrodynamic effects driven by ultralow applied field (E ∼ 1 V/cm), produced by the coupling of the large polarization to nematic birefringence and flow. Electrostatic self-interaction of the polarization charge renders the transition from the nematic phase mean field-like and weakly first order and controls the director field structure of the ferroelectric phase. Atomistic molecular dynamics simulation reveals short-range polar molecular interactions that favor ferroelectric ordering, including a tendency for head-to-tail association into polar, chain-like assemblies having polar lateral correlations. These results indicate a significant potential for transformative, new nematic physics, chemistry, and applications based on the enhanced understanding, development, and exploitation of molecular electrostatic interaction.
141 citations
TL;DR: It is shown that proteins implicated in cellular LLPS, including FUS, TDP-43, Brd4, Sox2, and Annexin A11, which form condensates at low salt concentrations, can reenter a phase-separated regime at high salt concentrations.
Abstract: Many cellular proteins have the ability to demix spontaneously from solution to form liquid condensates. These phase-separated structures form membraneless compartments in living cells and have wide-ranging roles in health and disease. Elucidating the molecular driving forces underlying liquid-liquid phase separation (LLPS) of proteins has thus become a key objective for understanding biological function and malfunction. Here we show that proteins implicated in cellular phase separation, such as FUS, TDP-43, and Annexin A11, which form condensates at low salt concentrations via homotypic multivalent interactions, also have the ability to undergo LLPS at high salt concentrations by reentering into a phase-separated regime. Through a combination of experiments and simulations, we demonstrate that phase separation in the high-salt regime is mainly driven by hydrophobic and non-ionic interactions. As such, it is mechanistically distinct from the low-salt regime, where condensates are stabilized by a broad mix of electrostatic, hydrophobic, and non-ionic forces. Our work thus expands the molecular grammar of interactions governing LLPS of cellular proteins and provides a new view on hydrophobicity and non-ionic interactions as non-specific driving forces for the condensation process, with important implications for the aberrant function, druggability, and material properties of biomolecular condensates.
138 citations
TL;DR: The high luminous, suitable wavelength, and good anti-water stability enable the solid solutions suitable for the application for underwater lighting to be reported.
Abstract: Underwater lighting is important for the exploration of the underwater world in different areas It is of great significance for developing underwater emitters with high penetrability, high luminous efficiency, good anti-water stability, and environmental friendliness Stable lead-free perovskite luminescent materials, represented by vacancy-ordered double perovskites, are worthy of research because they can almost meet the above requirements Here, lead-free perovskite variant solid solutions with the formula of Cs2 Sn1-x Tex Cl6 are reported Upon the exchange of Sn/Te ions, strong Jahn-Teller distortion of octahedra occurs in the lattice structure The combination of Te luminescent center and Jahn-Teller-like self-trapped excitons gives this material yellow-green luminescence with a wavelength of 580 nm and a high photoluminescence quantum yield of 954% Moreover, these solid solutions can withstand the extreme conditions of immersion in water probably due to the formation of amorphous alteration phase Such good anti-water stability is also supported by the molecule dynamics simulation result that no reaction occurs on the water/Cs2 SnCl6 interface The high luminous, suitable wavelength, and good anti-water stability enable the solid solutions suitable for the application for underwater lighting
135 citations
TL;DR: The findings suggest that protein−RNA complexes can robustly create lipid-free vesicle-like enclosures by phase separation, and suggest that liquid−liquid phase separation of multivalent intrinsically disordered protein− RNA complexes is ubiquitous in both natural and biomimetic systems.
Abstract: Liquid-liquid phase separation of multivalent intrinsically disordered protein-RNA complexes is ubiquitous in both natural and biomimetic systems So far, isotropic liquid droplets are the most commonly observed topology of RNA-protein condensates in experiments and simulations Here, by systematically studying the phase behavior of RNA-protein complexes across varied mixture compositions, we report a hollow vesicle-like condensate phase of nucleoprotein assemblies that is distinct from RNA-protein droplets We show that these vesicular condensates are stable at specific mixture compositions and concentration regimes within the phase diagram and are formed through the phase separation of anisotropic protein-RNA complexes Similar to membranes composed of amphiphilic lipids, these nucleoprotein-RNA vesicular membranes exhibit local ordering, size-dependent permeability, and selective encapsulation capacity without sacrificing their dynamic formation and dissolution in response to physicochemical stimuli Our findings suggest that protein-RNA complexes can robustly create lipid-free vesicle-like enclosures by phase separation
TL;DR: In this article, a (1-x)NBT-xBH transparent ceramic was fabricated by the solid state reaction method and X-ray diffraction analysis showed that NBT-based transparent ceramics exhibit a cubic-like perovskite structure and the solid solubility of BH in NBT reached to 0.15.
Abstract: A novel (1-x)Na0.5Bi0.5TiO3-xBaHfO3 (abbreviated as (1-x)NBT-xBH) transparent ceramic was fabricated by the solid state reaction method. X-ray diffraction analysis showed that NBT-based transparent ceramics exhibit a cubic-like perovskite structure and the solid solubility of BH in NBT reached to 0.15. The Landau-Devonshire theory and I-E curves revealed that the transition between the antiferroelectric like phase and the ferroelectric phase deeply relies on the variation of composition and free energy. One sample (x = 0.15) was found to show a high dielectric constant (˜2418±10%) over the temperature range 57–400 °C. These ceramics also exhibited a high discharge energy density (Wd) of 2.1 J/cm3 and a high maximum polarization Pm of 34 μC/cm2 under relatively low electric fields which were less than 175 kV/cm. There was also high transparency in the visible spectra (more than 0.5) when the sample thickness was 250 μm.
TL;DR: By using a high-pressure nitrogen-extraction (HPNE) strategy to assist crystallization, a wide processing window in the well-controlled printing process for preparing high-quality perovskites is achieved.
Abstract: Slot-die coating holds advantages over other large-scale technologies thanks to its potential for well-controlled, high-throughput, continuous roll-to-roll fabrication. Unfortunately, it is challenging to control thin.film uniformity over a large area while maintaining crystallization quality. Herein, by using a high-pressure nitrogen-extraction (HPNE) strategy to assist crystallization, a wide processing window in the well-controlled printing process for preparing high-quality perovskites is achieved. The yellow-phase perovskite generated by the HPNE acts as a crucial intermediate phase to produce large-area high-quality perovskite film. Furthermore, an ionic liquid is developed to passivate the perovskite surface to reduce surface defect density and to suppress carrier recombination, resulting in significantly increased efficiency to 22.7%, the highest for large-area fabrication. The strategies are successfully extended to large-area device fabrication, making it possible to produce a 40 × 40 mm2 module with stabilized PCE as high as 19.4%, the highest-efficiency for a large-area module to date.
TL;DR: In this article, the structural origins of photoinduced phase segregation in mixed-halide perovskite materials were explored, and it was shown that phase is not the sole determinant of optical stability.
Abstract: Summary Organic-inorganic metal-halide perovskite materials offer a promising route to reducing the dollars-per-watt cost of solar energy due to their good optoelectronic properties and facile, scalable processing. Compositional tuning allows for the preparation of absorbers with band gaps tailor-made for specific tandem and single-junction applications, but photoinduced phase segregation in mixed-halide materials leads to the formation of low-band-gap regions that reduce the voltage of devices. This work explores the structural origins of photoinduced phase segregation in FAyCs1−yPb(BrxI1−x)3 perovskite alloys. We use synchrotron X-ray diffraction to map the solvus between the cubic and cubic-tetragonal mixed-phase region and time-dependent photoluminescence to assess stability under illumination. We show that the correlation between crystallographic phase and phase-segregation behavior is imperfect, so phase is not the sole determinant of optical stability. Instead, we consider several possible mechanisms that could underlie the dependence of optical stability on perovskite composition.
TL;DR: In this article, the influence of thermal annealing on changes in the structural properties and phase composition of metallic nanostructures based on cobalt, as well as the possibilities of using an anode material for lithium ion batteries was investigated.
TL;DR: This review aims at providing insights into the fundamental understanding of the favourable synthetic conditions for the stabilization of metastable TMD crystals and at stimulating future advancements in the field of large-scale synthesis of materials with crystal phase control.
Abstract: The different polymorphic phases of transition metal dichalcogenides (TMDs) have attracted enormous interest in the last decade. The metastable metallic and small band gap phases of group VI TMDs displayed leading performance for electrocatalytic hydrogen evolution, high volumetric capacitance and some of them exhibit large gap quantum spin Hall (QSH) insulating behaviour. Metastable 1T(1T') phases require higher formation energy, as compared to the thermodynamically stable 2H phase, thus in standard chemical vapour deposition and vapour transport processes the materials normally grow in the 2H phases. Only destabilization of their 2H phase via external means, such as charge transfer or high electric field, allows the conversion of the crystal structure into the 1T(1T') phase. Bottom-up synthesis of materials in the 1T(1T') phases in measurable quantities would broaden their prospective applications and practical utilization. There is an emerging evidence that some of these 1T(1T') phases can be directly synthesized via bottom-up vapour- and liquid-phase methods. This review will provide an overview of the synthesis strategies which have been designed to achieve the crystal phase control in TMDs, and the chemical mechanisms that can drive the synthesis of metastable phases. We will provide a critical comparison between growth pathways in vapour- and liquid-phase synthesis techniques. Morphological and chemical characteristics of synthesized materials will be described along with their ability to act as electrocatalysts for the hydrogen evolution reaction from water. Phase stability and reversibility will be discussed and new potential applications will be introduced. This review aims at providing insights into the fundamental understanding of the favourable synthetic conditions for the stabilization of metastable TMD crystals and at stimulating future advancements in the field of large-scale synthesis of materials with crystal phase control.
TL;DR: In this article, the phase evolution of (1−x)TiO3-xSrTiOO3 (NBT-xST) solid solutions with x of 0−06 is revealed by characterizing the dielectric and ferroelectric properties.
TL;DR: In this article, a 2D metallic 1T-WS2 act as co-catalyst in assisting g-C3N4 nanotubes (NTs) obtained via a simple grinding method for promoting photocatalytic H2 production.
Abstract: Herein, we report that 2D metallic 1T-WS2 acts as co-catalyst in assisting g-C3N4 nanotubes (NTs) obtained via a simple grinding method for promoting photocatalytic H2 production. The 1T-WS2/g-C3N4 composite with optimum 27% 1T-WS2 displays a significantly improved photocatalytic H2 production rate (1021 μmol h−1 g−1), 17.6 times higher than g-C3N4 NTs. Besides, the apparent quantum efficiency (AQE) of 1T-WS2/g-C3N4 composite (27%) achieves 11.23% under light at λ = 370 nm. Meanwhile, the 1T-WS2/g-C3N4 composites present an excellent photocatalytic H2 production stability. The possible photocatalytic mechanism over 1T-WS2/g-C3N4 composites is proposed. Specifically, the photogenerated electrons from 1D g-C3N4 tubular nanostructure with open mesoporous morphology are migrated to conductive 1T-WS2 NSs quickly as electron acceptors along the 1D path. 1T-WS2 NSs can also offer abundant active sites on the edge and basal planes.
TL;DR: By employment of an external vertical magnetic field, ferromagnetic bowl-like MoS2 flake can afford electrons transmitting easily from glassy carbon electrode to active sites to drive HER, and thus perform magnetic HER enhancement.
Abstract: Numerous efforts in improving the hydrogen evolution reaction (HER) performance of transition metal dichalcogenides mostly focus on active sites exposing, vacancy engineering, and phase engineering...
01 Nov 2020
TL;DR: This work facilitates understanding the working mechanism of 2D PSCs deeply and offers an efficient way to further boosting their efficiency and stability by developing multiple-ring aromatic spacers.
Abstract: Two-dimensional (2D) perovskites with natural multi-quantum-well structure have been reported to offer better stability compared to 3D perovskites. However, the understanding of the exciton separation and transport mechanism in 2D perovskites and developing more efficient organic spacers remain considerable challenges, as the 2D perovskites exhibit large exciton binding energy due to quantum confinement. Here, a class of multiple-ring aromatic ammoniums, 1-naphthalenemethylammonium (NpMA) and 9-anthracenemethylammonium (AnMA), was developed as spacers for 2D Ruddlesden-Popper (RP) perovskite solar cells (PSCs). In addition to significantly enhanced stability, the device based on (NpMA)2(MA)n-1PbnI3n+1 (average n = 4) exhibits a champion efficiency of 17.25% and a high open-circuit voltage of 1.24 V. The outstanding photovoltaic performance could be ascribed to the ultrafast exciton migration (within 7 ps) from 2D phases to 3D-like phases, which were confirmed by charge carrier dynamics results, leading to efficient exciton separation, charge transportation, and collection. This work facilitates understanding the working mechanism of 2D PSCs in-depth and offers an efficient way to further boost their efficiency and stability by developing multiple-ring aromatic spacers.
TL;DR: It is shown that ferroelectric ordering of the molecules causes the formation of recently reported splay nematic liquid-crystalline phase, which drives an orientational ferroelastic transition via flexoelectric coupling.
Abstract: Ferroelectric ordering in liquids is a fundamental question of physics. Here, we show that ferroelectric ordering of the molecules causes the formation of recently reported splay nematic liquid-crystalline phase. As shown by dielectric spectroscopy, the transition between the uniaxial and the splay nematic phase has the characteristics of a ferroelectric phase transition, which drives an orientational ferroelastic transition via flexoelectric coupling. The polarity of the splay phase was proven by second harmonic generation imaging, which additionally allowed for determination of the splay modulation period to be of the order of 5-10 microns, also confirmed by polarized optical microscopy. The observations can be quantitatively described by a Landau-de Gennes type of macroscopic theory.
TL;DR: In this paper, the phase stability and coarsening kinetics of L12-type coherent precipitates in a Ni-30Co-13Fe-15Cr-6Al-6Ti-0.1B (at.
TL;DR: In this paper, the authors investigated the changes in crystal lattice, phase, composition and lattice strain up to 1000°C using both in situ high temperature X-ray diffraction (XRD) and transmission electron microscopy (TEM).
TL;DR: A novel interface-induced strategy is reported to achieve stable and high-percentage 1T MoS2 through highly active 1T-MoS2 /CoS2 hetero-nanostructure through fast kinetics and excellent catalytic activity induced by heterojunction.
Abstract: Metallic phase (1T) MoS2 has been regarded as an appealing material for hydrogen evolution reaction. In this work, a novel interface-induced strategy is reported to achieve stable and high-percentage 1T MoS2 through highly active 1T-MoS2 /CoS2 hetero-nanostructure. Herein, a large number of heterointerfaces can be obtained by interlinked 1T-MoS2 and CoS2 nanosheets in situ grown from the molybdate cobalt oxide nanorod under moderate conditions. Owing to the strong interaction between MoS2 and CoS2 , high-percentage of metallic-phase (1T) MoS2 of 76.6% can be achieved, leading to high electroconductivity and abundant active sites compared to 2H MoS2 . Furthermore, the interlinked MoS2 and CoS2 nanosheets can effectively disperse the nanosheets so as to enlarge the exposed active surface area. The near zero free energy of hydrogen adsorption at the heterointerface can also be achieved, indicating the fast kinetics and excellent catalytic activity induced by heterojunction. Therefore, when applied in hydrogen evolution reaction (HER), 1T-MoS2 /CoS2 heterostructure delivers low overpotential of 71 and 26 mV at the current density of 10 mA cm-2 with low Tafel slops of 60 and 43 mV dec-1 , respectively in alkaline and acidic conditions.
TL;DR: The latest experimental and theoretical studies on the fundamental physical properties of photoactive phase CsPbI3 have deepened the understanding of inorganic perovskites and will further advance inorganicperovskite for highly stable and efficient photovoltaics.
Abstract: Research on chemically stable inorganic perovskites has achieved rapid progress in terms of high efficiency exceeding 19% and high thermal stabilities, making it one of the most promising candidates for thermodynamically stable and high-efficiency perovskite solar cells. Among those inorganic perovskites, CsPbI3 with good chemical components stability possesses the suitable bandgap (≈1.7 eV) for single-junction and tandem solar cells. Comparing to the anisotropic organic cations, the isotropic cesium cation without hydrogen bond and cation orientation renders CsPbI3 exhibit unique optoelectronic properties. However, the unideal tolerance factor of CsPbI3 induces the challenges of different crystal phase competition and room temperature phase stability. Herein, the latest important developments regarding understanding of the crystal structure and phase of CsPbI3 perovskite are presented. The development of various solution chemistry approaches for depositing high-quality phase-pure CsPbI3 perovskite is summarized. Furthermore, some important phase stabilization strategies for black phase CsPbI3 are discussed. The latest experimental and theoretical studies on the fundamental physical properties of photoactive phase CsPbI3 have deepened the understanding of inorganic perovskites. The future development and research directions toward achieving highly stable CsPbI3 materials will further advance inorganic perovskite for highly stable and efficient photovoltaics.
TL;DR: Evidence of a strong ME coupling in a paramagnetic ferroelectric lanthanide coordination complex with magnetostrictive phenomenon is provided, offering a basis for developing high-density data storage and spintronic or low-consumption devices.
Abstract: Magnetoelectric (ME) materials combine magnetic and electric polarizabilities in the same phase, offering a basis for developing high-density data storage and spintronic or low-consumption devices owing to the possibility of triggering one property with the other. Such applications require strong interaction between the constitutive properties, a criterion that is rarely met in classical inorganic ME materials at room temperature. We provide evidence of a strong ME coupling in a paramagnetic ferroelectric lanthanide coordination complex with magnetostrictive phenomenon. The properties of this molecular material suggest that it may be competitive with inorganic magnetoelectrics.
TL;DR: In this article, a series of high entropy Ba(Zr0.2Ti 0.2Nb5,Ta5,V5+,Mo6+,W6+) perovskite oxides were synthesized by using a solid state reaction method.
TL;DR: A cost-effective multi-phase nanocomposite, facilely synthesized through smart self-assembly at high temperature, is developed as a near-ideal cathode of intermediate-temperature SOFCs, showing high OrR activity and the strong interaction between four phases in nanodomain creates a synergistic effect, leading to the superior ORR activity.
Abstract: An ideal solid oxide fuel cell (SOFC) cathode should meet multiple requirements, i.e., high activity for oxygen reduction reaction (ORR), good conductivity, favorable stability, and sound thermo-mechanical/chemical compatibility with electrolyte, while it is very challenging to achieve all these requirements based on a single-phase material. Herein, a cost-effective multi-phase nanocomposite, facilely synthesized through smart self-assembly at high temperature, is developed as a near-ideal cathode of intermediate-temperature SOFCs, showing high ORR activity (an area-specific resistance of ≈0.028 Ω cm2 and a power output of 1208 mW cm-2 at 650 °C), affordable conductivity (21.5 S cm-1 at 650 °C), favorable stability (560 h operation in single cell), excellent chemical compatibility with Sm0.2 Ce0.8 O1.9 electrolyte, and reduced thermal expansion coefficient (≈16.8 × 10-6 K-1 ). Such a nanocomposite (Sr0.9 Ce0.1 Fe0.8 Ni0.2 O3-δ ) is composed of a single perovskite main phase (77.2 wt%), a Ruddlesden-Popper (RP) second phase (13.3 wt%), and surface-decorated NiO (5.8 wt%) and CeO2 (3.7 wt%) minor phases. The RP phase promotes the oxygen bulk diffusion while NiO and CeO2 nanoparticles facilitate the oxygen surface process and O2- migration from the surface to the main phase, respectively. The strong interaction between four phases in nanodomain creates a synergistic effect, leading to the superior ORR activity.
TL;DR: In this paper, the authors investigated the phase separation of different sequences of a coarse-grained model for intrinsically disordered proteins and discovered a surprisingly rich phase behavior, including the formation of open phases consisting of aggregates, rather than a normal liquid.
Abstract: Phase separation of intrinsically disordered proteins is important for the formation of membraneless organelles or biomolecular condensates, which play key roles in the regulation of biochemical processes within cells. In this work, we investigated the phase separation of different sequences of a coarse-grained model for intrinsically disordered proteins and discovered a surprisingly rich phase behavior. We studied both the fraction of total hydrophobic parts and the distribution of hydrophobic parts. Not surprisingly, sequences with larger hydrophobic fractions showed conventional liquid-liquid phase separation. The location of the critical point was systematically influenced by the terminal beads of the sequence due to changes in interfacial composition and tension. For sequences with lower hydrophobicity, we observed not only conventional liquid-liquid phase separation but also re-entrant phase behavior in which the liquid phase density decreases at lower temperatures. For some sequences, we observed the formation of open phases consisting of aggregates, rather than a normal liquid. These aggregates had overall lower densities than the conventional liquid phases and exhibited complex geometries with large interconnected string-like or membrane-like clusters. Our findings suggest that minor alterations in the ordering of residues may lead to large changes in the phase behavior of the protein, a fact of significant potential relevance for biology.