Physics

We report an ultrahydrophobic biphenyl-extended pillar[6]arene with an extended cavity and enhanced fluorine content, allowing for extremely selective benzene separation from challenging azeotropic mixtures. The material selectively adsorbed trace amounts of benzene from cyclohexane and methanol with selectivities of 13 and 499, respectively. Benzene separation from methanol yields a record-high selectivity and purity of 99.80%, which is among the highest reported to date. Structural and adsorption studies show that a persistent porous macrocycle preferentially binds benzene within both intrinsic and extrinsic cavities via strong solid-state interactions. These findings show that adaptable macrocyclic molecular sieves can compete with extended frameworks for energy-efficient and sustainable hydrocarbon separations.

The rich diversity of transition-metal pairs bridged by oxygen contributes to the fascinating magnetic behaviors in high-entropy oxides (HEOs), while the complex interplay between multisite lattice configurations, spin states, and magnetic exchange interactions remains yet to be explored. Here, we report the Al 3+ -driven octahedral site preferential occupations and tunable magnetic frustration in spinel-type [5M 1/(5+ x ) Al x /(5+ x ) ] 3 O 4 ( x = 0–5; M = Cr/Fe/Mn/Zn/Co) HEOs. Nonmagnetic Al 3+ preferentially occupies octahedral sites (P B ), which significantly distorts the lattice with expansion in tetrahedral sites while shrinkage in P B –O. This structural evolution enables tuning of magnetic properties, e.g ., competition between ferromagnetic and antiferromagnetic states, spin glass, and spin-flop frustration states. Alternating-current susceptibility presents apparent spin frustration that follows a critical slowing-down model, which is suppressed when the Al 3+ level is beyond x = 2 because of the weakly frozen and disordered magnetic moments. These findings bring insights into modulating magnetic exchange interactions within multiple structural complexities for designing HEOs with tunable magnetic properties.

Supercapacitive swing adsorption (SSA) is a promising electrochemical CO2 capture technique, yet its development is limited by questions surrounding the mechanism of CO2 uptake. The phase and speciation of dissolved inorganic carbon in these systems has not been resolved, and open questions remain as to whether CO2 is captured as a gaseous or aqueous species, and if aqueous, whether the primary captured species is CO2, HCO3–, or CO32–. In this work, we investigate these questions in model SSA systems using solid-state nuclear magnetic resonance (NMR) spectroscopy and small-angle neutron scattering, and identify that the dominant species present are aqueous CO2 and HCO3–. Examination of variably wetted activated carbon/aqueous electrolyte systems dosed with CO2 indicates that a previously hypothesized uptake of gaseous CO2 in dry pores does not occur in the studied SSA systems. Instead, quantitative NMR spectroscopy measurements reveal a large pool of aqueous CO2 and HCO3– which adsorbs prior to charging and exceeds the observed uptake of supercapacitive CO2 capture. Observation of fast CO2:HCO3– exchange in this pool indicates that both species would be involved in any SSA process. These findings provide key insights into the mechanism of supercapacitive CO2 capture and will guide its future technological development as a method for the mitigation of CO2 emissions.

High Resolution Image Download MS PowerPoint Slide The discovery of new energetic materials is critical for advancing technologies from defense to private industry. However, experimental approaches remain slow and expensive, while computational alternatives require accurate material property inputs that are often costly to obtain, limiting their ability to efficiently predict detonation performance across a vast chemical space. We address this challenge through an active learning strategy that integrates density functional theory calculations, thermochemical modeling, message-passing neural networks, and Bayesian optimization. The resulting high-throughput workflow iteratively expands the training data set by selecting new molecules in a targeted manner that balances the exploration of broad chemical space with the exploitation of promising high-performing candidates. This approach yields the largest publicly available database of potential CHNO explosives drawn from an initial pool of more than 70 billion candidates and a generalizable surrogate model capable of accurately predicting detonation performance ( R 2 > 0.98). Feature importance analysis on this largest-to-date data set reveals that oxygen balance is the dominant driver of detonation performance, complemented by contributions from local electronic structure, density, and the presence of specific functional groups. Cheminformatics analysis highlights how energetic materials with similar performance metrics tend to cluster in distinct chemical spaces, offering a clearer direction for future synthesis studies. Together, the surrogate model, database, and resulting chemical insights provide a valuable foundation for high-throughput screening and targeted discovery of new energetic materials spanning diverse and previously unexplored regions of chemical space.

We report the synthesis of EuBi 2 single crystals and their magnetic and electronic properties. Plate-like crystals were grown in excess bismuth, and X-ray diffraction data confirm the previously reported tetragonal space group, I 4 1 /amd (No. 141). A Néel temperature of T N = 18.6 K was determined from the specific heat data, and corresponding anomalies occur in the magnetization and resistivity. We only observe one magnetic transition in zero magnetic field. The magnetization data above 70 K are well described by a Curie-Weiss model with a Weiss temperature of Θ CW ≈ −35 K and an effective moment near that of the expected spin-only moment of Eu 2+ (S = 7/2). Isothermal magnetization measurements reveal field-induced transitions for H||[100], including a hysteretic spin-flop centered at 10.1 T and a change in slope at 12 T and 2 K. However, while the isothermal magnetization for H||[110] displays nonlinear behavior, discrete metamagnetic transitions are not observed for H||[110] or H||[001], indicating significant magnetic anisotropy. The magnetization does not saturate by 13.5 T for any orientation. EuBi 2 is metallic and our crystals possess an in-plane residual resistivity ratio of ⍴ 300 K /⍴ 2 K ≈ 40. Single crystal neutron diffraction data reveal a large magnetic unit cell and non-trivial antiferromagnetic ordering. These results demonstrate that strong antiferromagnetic coupling drives complex magnetism in EuBi 2 .

Topological properties and topological superconductivity in real materials have attracted intensive experimental and theoretical attentions recently. The topological electronic properties of pressure-induced superconductors ${\mathrm{BiH}}_{2}$ have been studied based on first-principles electronic structure calculations. Recent experiments have revealed that ${\mathrm{BiH}}_{2}$ exhibits five distinct phases under high pressure, our studies show that $Cmcm\text{\ensuremath{-}}{\mathrm{BiH}}_{2}, Pnma\text{\ensuremath{-}}{\mathrm{BiH}}_{2}, Pnnm\text{\ensuremath{-}}{\mathrm{BiH}}_{2}$, and $P{2}_{1}/m\text{\ensuremath{-}}{\mathrm{BiH}}_{2}$ are all topological metals defined on curved Fermi levels, while the $P{2}_{1}{2}_{1}{2}_{1}\text{\ensuremath{-}}{\mathrm{BiH}}_{2}$ holds Weyl points near the Fermi level. The topological surface states (TSSs) and Fermi arcs of ${\mathrm{BiH}}_{2}$ right cross the Fermi level and hold helical spin textures. Considering the fact that the ${\mathrm{BiH}}_{2}$ exhibit high superconducting transition temperatures (${T}_{c}$) of $\ensuremath{\sim}70$ K under pressure confirmed by recent experiments, the superconducting bulks will induce superconductivity in the TSSs via the proximity effect. Thus, the hydride superconductors ${\mathrm{BiH}}_{2}$ may provide a promising platform for exploring topological superconductivity and Majorana zero modes.

Antiferromagnetic kagome metals remain far less explored than their ferromagnetic counterparts, despite predictions of unconventional spin textures and emergent transport phenomena. Here, the authors report the growth of single crystals of the metallic kagome antiferromagnet CrRhAs and investigate its magnetic and electronic properties. While no nonlinear Hall effect is observed, Hall measurements reveal an unexpected sign reversal upon changing the current direction, together with a pronounced enhancement below the antiferromagnetic transition. These findings point to a strong coupling between magnetic order and an anisotropic electronic structure, highlighting CrRhAs as a promising platform for exploring transport phenomena in antiferromagnetic kagome metals.

$\text{G}{\text{a}}_{2}{\text{O}}_{3}$/GaAs heterojunctions are emerging as promising candidates for next-generation power electronics, photonics, and energy devices, leveraging the high breakdown voltage and thermal stability of $\text{G}{\text{a}}_{2}{\text{O}}_{3}$ alongside the mature technology, high hole mobility, and high refractive index of GaAs. The efficiency of these devices depends strongly on the band alignment between the two materials, however both type-I and type-II alignment have been reported in the literature for these heterostructures. To address this ambiguity, we use hybrid density functional theory to systematically investigate the band alignment at GaAs/$\text{G}{\text{a}}_{2}{\text{O}}_{3}$ interfaces, focusing on the role of interface chemistry. By considering Ga-O-, As-, and As-O-rich interfaces both in amorphous and crystalline $\text{G}{\text{a}}_{2}{\text{O}}_{3}$ phases, we demonstrate that interface stoichiometry determines the alignment type: Ga-O-rich interfaces exhibit type-II alignment with large valence band offsets (\ensuremath{\sim}3.1 eV), while As-rich and As-O-rich interfaces favor type-I alignment with reduced offsets (\ensuremath{\sim}2.3--2.6 eV). These trends are attributed to interface dipole formation driven by bonding configuration. Our findings provide insight into the relationship between chemistry and band alignment in GaAs/$\text{G}{\text{a}}_{2}{\text{O}}_{3}$ heterostructures, enabling targeted optimization for specific device applications.

ABSTRACT Aqueous zinc batteries (AZBs) offer safety and cost‐effectiveness for large‐scale energy storage, yet their development is hindered by calendar aging originating from spontaneous Zn corrosion in aqueous electrolytes. This issue is especially critical for grid batteries, which remain idle for extended periods. Here, we present a strategy of suspension electrolyte to improve the calendar performance of AZBs by dispersing only 3 wt.% of Al 2 O 3 nanoparticles into a conventional ZnSO 4 electrolyte. Under a calendar‐aging protocol, Zn||Cu cells with Al 2 O 3 suspension electrolyte achieve a threefold enhancement in calendar lifespan and significantly improve Coulombic efficiency from 91.7% to 97.1%. We demonstrate that the Al 2 O 3 suspension electrolyte forms a protective interfacial layer at the Zn anode that serves as a physical barrier while absorbing water, H + , and OH − ions to mitigate water reactivity and buffer pH fluctuations, thereby effectively suppressing parasitic corrosion. Furthermore, Zn||MnO 2 full cells with Al 2 O 3 suspension electrolyte exhibit higher specific capacities across all rates and retain over 100 mAh g −1 at 1 A g −1 for 1500 cycles. These findings highlight suspension electrolyte as a low‐cost and effective approach to advancing AZBs for long‐duration large‐scale energy storage.