•Recent research on dielectric transition and ferroelectricity is overviewed.•Basic concepts and fundamentals of the two properties are introduced.•Structural changes during the phase transitions are ...discussed.
Structural phase transition in solid-state materials is an underlying factor for emergence and evolution of a number of important physical/chemical properties. In this review, we summarize recent achievements on two types of structural phase transition-associated properties, i.e., dielectric transition and ferroelectricity, in coordination compounds. The basic concepts and fundamentals of structural phase transition and the two properties are briefly introduced. This review aims to reveal the role of the structural phase transitions on bulk properties and afford a perspective on the connections among multiple topics of coordination chemistry from the structural phase transition viewpoint. It would be appealing to researchers in multidisciplinary fields such as coordination chemistry, crystal engineering, supramolecular chemistry, condensed matter physics, responsive materials and molecular machines.
Spintronics is the most promising technology to develop alternative multi-functional, high-speed, low-energy electronic devices. Due to their unusual physical characteristics, emerging ...two-dimensional (2D) materials provide a new platform for exploring novel spintronic devices. Recently, 2D spintronics has made great progress in both theoretical and experimental researches. Here, the progress of 2D spintronics has been reviewed. In the last, the current challenges and future opportunities have been pointed out in this field.
Engineering single-atom electrocatalysts with high-loading amount holds great promise in energy conversion and storage application. Herein, we report a facile and economical approach to achieve an ...unprecedented high loading of single Ir atoms, up to ∼18wt%, on the nickel oxide (NiO) matrix as the electrocatalyst for oxygen evolution reaction (OER). It exhibits an overpotential of 215 mV at 10 mA cm–2 and a remarkable OER current density in alkaline electrolyte, surpassing NiO and IrO2 by 57 times and 46 times at 1.49 V vs RHE, respectively. Systematic characterizations, including X-ray absorption spectroscopy and aberration-corrected Z-contrast imaging, demonstrate that the Ir atoms are atomically dispersed at the outermost surface of NiO and are stabilized by covalent Ir–O bonding, which induces the isolated Ir atoms to form a favorable ∼4+ oxidation state. Density functional theory calculations reveal that the substituted single Ir atom not only serves as the active site for OER but also activates the surface reactivity of NiO, which thus leads to the dramatically improved OER performance. This synthesis method of developing high-loading single-atom catalysts can be extended to other single-atom catalysts and paves the way for industrial applications of single-atom catalysts.
Direct detection of circularly polarized light (CPL) is a challenging task due to limited materials and ambiguous structure–property relationships that lead to low distinguishability of the light ...helicities. Perovskite ferroelectric semiconductors incorporating chirality provide new opportunities in dealing with this issue. Herein, a pair of 2D chiral perovskite ferroelectrics is reported, which have enhanced CPL detection performance due to interplays among lattice, photon, charge, spin, and orbit. The chirality‐transfer‐induced chiral&polar ferroelectric phase enhances the asymmetric nature of the photoactive sublattice and achieves a switchable self‐powered detection via the bulk photovoltaic effect. The single‐crystal‐based device exhibits a CPL‐sensitive detection performance under 430 nm with an asymmetric factor of 0.20 for left‐ and right‐CPL differentiation, about two times that of the pure chiral counterparts. The enhanced CPL detection performance is ascribed to the Rashba–Dresselhaus effect that originates from the bulk inversion asymmetry and strong spin–orbit coupling, shown with a large Rashba coefficient, which is demonstrated by density functional theory calculation and circularly polarized light excited photoluminescence measurement. These results provide new perspectives on chiral Rashba ferroelectric semiconductors for direct CPL detection and ferroelectrics‐based chiroptics and spintronics.
A pair of 2D chiral perovskite Rashba ferroelectric semiconductors is reported. The fabricated single‐crystal device responds to circularly polarized light (CPL) under 430 nm with an anisotropy factor of 0.20 for the left‐ and right‐CPL differentiation, about two times of reported pure chiral counterparts. The enhanced performance is ascribed to the Rashba–Dresselhaus effect with a large Rashba coefficient of 0.93 eV Å.
We propose an efficient method to verify the upper bound of the fraction of counts caused by multiphoton pulses in practical quantum key distribution using weak coherent light, given whatever type of ...Eve's action. The protocol simply uses two coherent states for the signal pulses and vacuum for the decoy pulse. Our verified upper bound is sufficiently tight for quantum key distribution with a very lossy channel, in both the asymptotic and nonasymptotic case. So far our protocol is the only decoy-state protocol that works efficiently for currently existing setups.
Developing advanced superwetting oil/water separation materials with controlled wettability, excellent selectivity and sustainable separation is a persistent pursuit for researchers. Recently, smart ...materials have been highly anticipated to enable the sustainable treatment of oil spills and oily wastewater. According to their different response mechanisms, smart materials are mainly divided into stimulus responsive and prewetting induced types. The stimulus responsive smart materials can reversibly switch interfacial wettability between superhydrophobicity and superhydrophilicity in accordance with the external stimulus. Alternatively, prewetting induced smart materials can realize on-demand oil/water separation without continuous external stimulus, given that their responses are only water or oil, which can be obtained directly from oil/water mixtures. Even though most smart materials have exhibited remarkable potential in sustainably solving oil spills and purifying oily wastewater, these extremely significant and crucial research advancements have rarely been summarized and reported in the recent literature. Herein, we present an in-depth discussion and systematic summary of the work done thus far in the development of smart materials for oil/water separation. Firstly, the fundamental theory of special wettability, the mechanism of oil/water separation, and the "oil-removing" materials and "water-removing" materials with single wettability are discussed, respectively. Then, Janus materials with asymmetrical wettability are also discussed. Particularly, the current developments of smart materials with switchable wettability are emphatically reviewed, such as their preparation principles, main responsive factors, representative works, design ideas, fabrication strategies, and the role of special wettability in oil/water separation. Finally, a comprehensive summary and future outlook of smart materials are provided, including their advantages and disadvantages, the remaining challenges, and prospects for the future of this subject. It is expected that this comprehensive overview will provide a fresh understanding and important guidance for future research on smart oil/water separation materials.
Smart materials with convertible wettability interfaces enable to sustainably treat oil spills and purify oily wastewater.
Metal materials are susceptible to the influence of environmental media, and chemical or electrochemical multiphase reactions occur on the metal surface, resulting in the corrosion of metal ...materials, which can directly damage the geometry and reduce the physical properties of metal materials. This corrosion damage can seriously affect the long-term use of metal materials in marine equipment and the aerospace industry, and other fields. Inspired by the special microstructure and slippery properties of natural nepenthes intine, researchers have prepared slippery liquid-infused porous surfaces (SLIPS) with a stable continuous lubricant layer by injecting low-surface-energy lubricants into a substrate with a micro/nano-porous structure. This surface has excellent hydrophobicity, low friction, non-adhesiveness, and self-healing properties. The broad application prospects of SLIPS in the fields of anti-corrosion, anti-icing, anti-bacteria, and anti-fouling have made it a hot research topic directing the study of biomimetic materials at present. However, SLIPS are susceptible to environmental shear forces, such as ocean flow or extraneous fluids, resulting in destruction of the porous structure and loss of surface lubricant, thereby depriving SLIPS of the ability to protect metals from corrosion. Therefore, it is important for metal corrosion protection to find ways to improve the stability and extend the service life of SLIPS. Over the last several years, research into and development of SLIPS have come a long way. Herein, a summary of available reports on SLIPS is given in terms of design principles and their performance characteristics, the construction of rough/porous substrate structures, the choice of low-surface-energy modifiers and lubricants, and lubricant infusion methods. Ways of constructing different substrate structures and the characteristics, advantages, and disadvantages of choosing various modifiers and lubricants to prepare the surface are compared. Finally, a comprehensive summary and outlook of SLIPS with anti-corrosion properties are provided. We are convinced that a comprehensive review of SLIPS will provide important guidance and strong reference for the design and preparation of green and economical SLIPS with anti-corrosion capabilities in the future.
Slippery liquid-infused porous surfaces with dense lubricant layer and non-adhesive enable to effectively avoid metal corrosion.
Discharge of oily sewage and frequent oil spills have caused serious harm to human production, life, and ecological environment. Due to the presence of a large number of surfactants in water, these ...oil-water mixtures are easy to form oil-in-water emulsion, which is difficult to separate by traditional methods. At the same time, the water-soluble pollutants such as dyes and heavy metal ions in oily wastewater also cause great harm to the human body and the environment. A pine nut shell is a kind of common domestic waste material. Herein, an underwater superoleophobic pine nut shell membrane (PNSM) was prepared by the simple pumping filtration method, which realized the separation of oil-in-water emulsion and adsorption of dyes and heavy metal ions. In addition, the filter membrane can be used for separating corrosive emulsions of strong acid, strong alkali, and 3.5% NaCl solutions (simulated seawater). Besides, the PNSM showed excellent toughness and flexibility. Due to the abovementioned performance, this cost-efficient and environmentally friendly membrane can be a promising candidate for multifunctional oily water remediation.
Lightweight conductive foam: An ultralight conductive nanocomposite foam with a density of 0.05 g cm−3 (see SEM image) was successfully prepared based on multi‐walled carbon nanotubes and rigid ...polyurethane. An interesting density‐dependent conductor–insulator transition was observed in this ultralight composite, which reveals the weight‐lightening limit of a conductive polymer composite.
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