The Goos-Hänchen (GH) shift and the Imbert-Fedorov (IF) shift are optical phenomena which describe the longitudinal and transverse lateral shifts at the reflection interface, respectively. Here, we ...predict the GH and IF shifts in Weyl semimetals (WSMs)-a promising material harboring low energy Weyl fermions, a massless fermionic cousin of photons. Our results show that the GH shift in WSMs is valley independent, which is analogous to that discovered in a 2D relativistic material-graphene. However, the IF shift has never been explored in nonoptical systems, and here we show that it is valley dependent. Furthermore, we find that the IF shift actually originates from the topological effect of the system. Experimentally, the topological IF shift can be utilized to characterize the Weyl semimetals, design valleytronic devices of high efficiency, and measure the Berry curvature.
We report on a theoretical study of spin-dependent electron transport through single-helical molecules connected by two nonmagnetic electrodes, and explain the experiment of significant ...spin-selective phenomenon observed in α-helical protein and the contradictory results between the protein and single-stranded DNA. Our results reveal that the α-helical protein is an efficient spin filter and the spin polarization is robust against the disorder. These results are in excellent agreement with recent experiments Mishra D, et al. (2013) Proc Natl Acad Sci USA 110(37):14872–14876; Göhler B, et al. (2011) Science 331(6019):894–897 and may facilitate engineering of chiral-based spintronic devices.
High‐performance flexible pressure sensors are highly demanded for artificial tactile sensing. Using ionic conductors as the dielectric layer has enabled ionotronic pressure sensors with high ...sensitivities owing to giant capacitance of the electric double layer (EDL) formed at the ionic conductor/electronic conductor interface. However, conventional ionotronic sensors suffer from leakage, which greatly hinders long‐term stability and practical applications. Herein, a leakage‐free polyelectrolyte elastomer as the dielectric layer for ionotronic sensors is synthesized. The mechanical and electrical properties of the polyelectrolyte elastomer are optimized, a micropyramid array is constructed, and it is used as the dielectric layer for an ionotronic pressure sensor with marked performances. The obtained sensor exhibits a sensitivity of 69.6 kPa−1, a high upper detecting limit on the order of 1 MPa, a fast response/recovery speed of ≈6 ms, and excellent stability under both static and dynamic loads. Notably, the sensor retains a high sensitivity of 4.96 kPa−1 at 500 kPa, and its broad sensing range within high‐pressure realm enables a brand‐new coding strategy. The applications of the sensor as a wearable keyboard and a quasicontinuous controller for a robotic arm are demonstrated. Durable and highly sensitive ionotronic sensors potentialize high‐performance artificial skins for soft robots, human–machine interfaces, and beyond.
A microstructured leakage‐free polyelectrolyte elastomer is synthesized for ionotronic sensors, achieving a sensitivity of 69.6 kPa−1 and excellent stability under both static and dynamic loads. The broad sensing range of the sensor within the high‐pressure realm enables a brand‐new coding strategy. A wearable keyboard and a quasicontinuous controller for a robotic arm are demonstrated.
Discrete organopalladium coordination cages have shown great potential in applications ranging from molecular recognition and sensing, drug delivery to enzymatic catalysis. While many of the known ...organopalladium cages are homoleptic structures with regular polyhedral shapes and symmetric inner cavities, heteroleptic cages with complex architectures and new functions coming from their anisotropic cavities have received an increasing attention recently. In this concept article, we discuss a powerful combinatorial coordination self‐assembly strategy toward the construction of a family of organopalladium cages, including both homoleptic and heteroleptic ones, from a given library of ligands. Within such a cage family, the heteroleptic cages often feature systematically fine‐tuned structures and emergent properties, distinct from their parent homoleptic counterparts. We hope the concepts and examples provided in this article can offer some rational guidance for the design of new coordination cages toward advanced functions.
Combinatorial coordination self‐assembly is a powerful tool to create the lower‐symmetric coordination cages with increasing structural complexities and advanced functions. In this concept article, we define and summarized the strategy for the combinatorial self‐assembled PdII coordination cages. Emergent functions on some selected PdII coordination cages were also introduced with an aim of emphasizing the advantages of the heteroleptic cages.
Chiral luminescent lanthanide–organic cages have many potential applications in enantioselective recognition, sensing, and asymmetric catalysis. However, due to the paucity of structures and their ...limited cavities, host–guest chemistry with lanthanide–organic cages has remained elusive so far. Herein, we report a guest-driven self-assembly and chiral induction approach for the construction of otherwise inaccessible Ln4L4-type (Ln = lanthanide ions, i.e., EuIII, TbIII; L = ligand) tetrahedral hosts. Single crystal analyses on a series of host–guest complexes reveal remarkable guest-adaptive cavity breathing on the tetrahedral cages, reflecting the advantage of the variation tolerance on coordination geometry of the f-elements. Meanwhile, noncovalent confinement of pyrene within the lanthanide cage not only leads to diminishment of its excimer emission but also facilitates guest to host energy transfer, opening up a new sensitization window for the lanthanide luminescence on the cage. Moreover, stereoselective self-assembly of either Λ4- or Δ4- type Eu4L4 cages has been realized via chiral induction with R/S-BINOL or R/S-SPOL templates, as confirmed by NMR, circular dichroism (CD), and circularly polarized luminescence (CPL) with high dissymmetry factors (g lum) up to ±0.125.
The experiment that the high spin selectivity and the length-dependent spin polarization are observed in double-stranded DNA Science 331, 894 (2011), is elucidated by considering the combination of ...the spin-orbit coupling, the environment-induced dephasing, and the helical symmetry. We show that the spin polarization in double-stranded DNA is significant even in the case of weak spin-orbit coupling, while no spin polarization appears in single-stranded DNA. Furthermore, the underlying physical mechanism and the parameter dependence of the spin polarization are studied.
Conversion‐alloying type anode materials like metal sulfides draw great attention due to their considerable theoretical capacity for sodium‐ion batteries (SIBs) and potassium‐ion batteries (PIBs). ...However, poor conductivity, severe volume change, and harmful aggregation of the material during charge/discharge lead to unsatisfying electrochemical performance. Herein, a facile and green strategy for yolk–shell structure based on the principle of metal evaporation is proposed. SnS2 nanoparticle is encapsulated in nitrogen‐doped hollow carbon nanobox (SnS2@C). The carbon nanoboxes accommodate the volume change and aggregation of SnS2 during cycling, and form 3D continuous conductive carbon matrix by close contact. The well‐designed structure benefits greatly in conductivity and structural stability of the material. As expected, SnS2@C exhibits considerable capacity, superior cycling stability, and excellent rate capability in both SIBs and PIBs. Additionally, in situ Raman technology is unprecedentedly conducted to investigate the phase evolution of polysulfides. This work provides an avenue for facilely constructing stable and high‐capacity metal dichalcogenide based anodes materials with optimized structure engineering. The proposed in‐depth electrochemical measurements coupled with in situ and ex situ characterizations will provide fundamental understandings for the storage mechanism of metal dichalcogenides.
The successful structural engineering of SnS2@C gives effective accommodation to the volume change of SnS2 during charge/discharge as well as the enhancement of the conductivity. Owing to the positive effect of the N‐doped carbon nanoboxes with interior void space, the as‐prepared SnS2@C anode with satisfying capacity exhibits excellent cycling stability and superior rate capability.
Luminescent lanthanide‐containing compounds have a lot of stimulating applications. However, the fine‐tuning of the optical properties of multi‐nuclear lanthanide edifices is still a big challenge. ...We report here the coordination self‐assembly of a group of bright luminescent lanthanide organic polyhedra (LOPs) with record high emission quantum yields, by using two fully‐conjugated ligands featuring the triazole‐pyridine‐amido (tpa) chelating moiety, easily‐accessible from the “Click” reaction. The self‐assembled LOPs are characterized by NMR spectroscopy, high‐resolution ESI‐TOF‐MS, and X‐ray crystallography. Interestingly, inter‐metal energy transfer (ET) is confirmed on the mixed‐lanthanide polyhedral molecules, though the metal centers are separated nearly 2 nm apart. A feasible ratiometric luminescent thermometer, with work range from cryogenic to physiological temperatures, has been demonstrated with the mixed Eu/Tb LOPs. We envisage these molecular‐level bright luminescent LOPs have great application potential in displaying, labelling/imaging, up‐conversion materials etc.
Red hot! A group of bright luminescent lanthanide organic polyhedra (LOPs) with record‐high emission quantum yields are developed. A feasible ratiometric luminescent thermometer, with working range from cryogenic to physiological temperatures, has been demonstrated with the mixed Eu/Tb LOPs.
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.
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