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Exposure to toxic metals and metalloids is a significant public health concern and can seriously affect human health. The aim of this study was to establish the presence of toxic metals and metalloids in the urine of non‐professional sportsmen who participated in a mountain ultramarathon using a benchtop total reflection x‐ray fluorescence (TXRF) system. TXRF allows for easy and rapid sample preparation and is therefore a potential candidate for simple and cost‐effective analysis. In this work, the TXRF‐Mo system was used for multielement analysis of the urine samples of 21 non‐professional athletes who ran a 53 km mountain ultra‐marathon. Urine samples were collected at four time points, at the beginning of the race (pre‐race samples), immediately, and 12 and 24 h post‐race. Al, As, Ba, Ni, Pb, Rb, Sr, V, and Tl were detected in the collected urine samples. The accuracy and precision of the proposed methods were verified by the analysis of reference materials (Seronorm™ Trace Elements Urine Level 2). The TXRF results were in agreement with the reference values and no significant differences were observed at the 95% confidence level. The detection limits for the elements of interest were also reasonable considering their concentration ranges in real samples. Changes were observed over time with increasing average urinary metals and metalloids levels, but only two significant results, were an increase in As and Rb. The results indicate a high degree of inter‐subject variability. The results obtained show that the content of toxic metals and metalloids increases in the urine samples collected after the race, which could confirm the statement that physical activity can increase the excretion of toxic metals and metalloids from the body. The simplicity of the TXRF method as well as its fast performance make it suitable for routine analysis. [ABSTRACT FROM AUTHOR]

Pulsed solid‐state lasers comprise 2D materials as saturable absorbers that contain transparent windows of the atmosphere and characteristic fingerprint spectra of several vital molecules that are significant in various applications and research. Over the past few decades, significant progress has been made in the development of narrow pulse width, high energy, high average output power, high efficiency, and simple construction of passively Q‐switched and mode‐locked lasers with 2D materials as saturable absorbers. This review summarizes the development of 2D materials, including graphene, transition metal dichalcogenides, black phosphorus, topological insulators, and MXenes, as modulator devices for solid‐state lasers owing to their broadband operation, excellent nonlinear optical response, low recovery time, ultrafast dynamic processing, and easy fabrication. Then, some new emerging and representative applications of pulsed solid‐state lasers are introduced and illustrated such as laser surgery, material processing, and lidar. Finally, future challenges and perspectives of pulsed solid‐state lasers with 2D materials‐based saturable absorbers are analyzed and addressed. The rapid development of pulsed solid‐state lasers with the continuous improvement of modulation technology is expected to expand opportunities for application in industry, scientific, medical, and other areas. [ABSTRACT FROM AUTHOR]

HgTe has been considered to be one of the most versatile topological materials. Depending on the in‐plane strain, Weyl and Dirac semi‐metal, as well as topological insulator phases, are feasible. Here, for the first time it is reported, that an InAs:S substrate promotes an initial 2D growth of a ZnTe thin layer and subsequent high crystalline quality ZnTe/CdTe superlattices serve as a smooth and continuous virtual substrate for the growth of (Cd,Hg)Te/HgTe/(Cd,Hg)Te heterostructures with unstrained quantum well HgTe (topological insulator) and compressively strained bulk HgTe (Weyl semimetal) by molecular beam epitaxy. Compared with the superlattices previously grown on GaAs substrates, the quantum well and bulk heterostructures exhibit homogeneous surfaces with root mean square roughnesses of 0.88–0.93 nm, which is three times lower than those observed for 3D islands (2.7–3.4 nm) on GaAs substrates. Additionally, magnetotransport measurements confirm high electronic quality and demonstrate that the S‐doped InAs substrate can be used as an effective back gate. These results manifest a (big) step forward toward the improvement of micro‐ and nanometer‐sized top‐ and back‐gated device fabrication on topological materials. [ABSTRACT FROM AUTHOR]

Layered ternary type‐II Weyl semimetals demonstrate promising applications in high‐performance and broadband optoelectronics, therefore it is crucial to gain insights into their photocarriers’ dynamics. In this work, the probing polarization dependence of non‐equilibrium dynamics in NbIrTe4 is investigated by using transient reflectivity spectroscopy. Following photoexcitation at 3.18 eV, the dynamical response of 1.59 eV probe pulse exhibits a strong dependence on probe polarization. The relaxation comprises two components: a rapid recovery of ≈0.6 ps attributed to the electron–phonon scattering, and an anomalous slow recovery spanning hundreds of picoseconds attributed to the photoinduced quasi‐particle. The polarization dependence of rapid relaxation time τ is indicative of the in‐plane anisotropy of electron–phonon coupling in NbIrTe4. The slow relaxation modulated by a latest reported 16 cm−1 coherent phonon also shows strong probing polarization dependence, further revealing the anisotropic nature of electron–phonon coupling and the possibility of anisotropic lattice distortion, as well as photoinduced polaron, under ultrafast photoexcitation in NbIrTe4. The dynamical anisotropy in NbIrTe4 has provided valuable guidance for the application of NbIrTe4 in polarization‐sensitive nonlinear optics or optoelectronic devices and offers insights into the unique carrier transport as well as phonon transport properties of this newly established topological material. [ABSTRACT FROM AUTHOR]

High theoretical capacity, stabilized and layered 2H phase molybdenum disulfide (2H) is regarded as a promising material for superior kinetics anode in sodium ion battery, but the inherent semiconducting properties and sluggish sodium ions diffusion limit the development of 2H based anode. Hence, this study builds a unique metalloid phase with high electronic conductivity and suitable layer structure by screening non‐metallic carbon atoms doped in 2H (2H‐C). As experimental and simulation results, 2H‐C of metalloid properties after carbon atom modulation exhibit superior sodium storage kinetics and reversibility by a unique mechanism that promotes ion intercalation under high voltage window, and further good for the later uniformly conversion at lower voltage (intercalation‐conversion mechanism). The 2H‐C anode material delivers a remarkable reversible capacity of 156 mAh g−1 at ultra‐high 100.0 A g−1, long‐term life of 6000 cycles, and superior performance at low temperatures of −10 °C. Otherwise, 2H‐C/Na3V2(PO4)3 full cell also performs charge/discharge capacity of 80.0/76.7 mAh g−1 with 87% capacity retention after 140 cycles at 0 °C. This discovery further explores the unique mechanism and application of 2D layered materials in sodium‐ion battery anodes for fast kinetics under extreme conditions. [ABSTRACT FROM AUTHOR]

Topological materials are currently considered excellent catalysts for heterogeneous processes because of their surface metallic states and excellent carrier mobility. This work will show that cubic palladium bronze LaPd3S4 is an ideal topological material with multifold fermions, Fermi arcs on the (001) surface, and high catalytic performance for electrochemical hydrogen evolution reactions (HER). A direct correlation has been discovered between the position of the multifold fermions (related to the Fermi level) and Gibbs free energy (ΔGH*). Moreover, by applying the vertical electric field and uniaxial strain to the LaPd3S4, the multifold fermions disappear, and the |ΔGH*| increases, weakening the HER activity. This correlation establishes a clear connection between increased catalytic performance and topological states and fully elucidates the underlying process in topological catalysis. [ABSTRACT FROM AUTHOR]

Herein, via first‐principle calculations and theoretical analysis, a new Dirac semimetal carbon system called C32, which is composed of pentagonal, hexagonal, heptagonal, and octagonal carbon rings is systematically investigated. The stability of C32 is verified by calculating the phonon dispersion, elastic constants, etc., and an appropriate pathway for experimental synthesis is proposed. Besides, it is discovered that the system holds the quadruple rotation and inversion symmetry, resulting in the emergence of eight twisted Dirac cones (D1 and D2) with a highly anisotropic Fermi velocity from 3.83 × 105 to 8.96 × 105 m s−1 along different k directions. To substantiate the semimetallic nature of C32, its nontrivial topological properties are confirmed through the presence of topologically protected edge states, and the nonzero ℤ2 topological invariant. More importantly, by introducing biaxial strain, it is uncovered that Dirac cones can gradually evolve into a nodal line, and the perfect nodal line can be obtained when the biaxial strain is 13.3%. Furthermore, by constructing the tight‐binding model, the appearance of the Dirac cone is perfectly repeated and its evolution into the nodal line under biaxial strain is explained. [ABSTRACT FROM AUTHOR]

In this review, the thermoelectric properties in nodal‐point semimetals with two bands are discussed. For the two‐dimensional (2D) cases, it is shown that the expressions of the thermoelectric coefficients take different values depending on the nature of the scattering mechanism responsible for transport, by considering examples of short‐ranged disorder potential and screened charged impurities. An anisotropy in the energy dispersion spectrum invariably affects the thermopower quite significantly, as illustrated by the results for a node of semi‐Dirac semimetal and a single valley of graphene. The scenario when a magnetic field of magnitude B$B$ is applied perpendicular to the plane of the 2D semimetal is also considered. The computations for the three‐dimensional (3D) cases necessarily involve the inclusion of nontrivial Berry phase effects. In addition to demonstrating the expressions for the response tensors, the exotic behavior observed in planar Hall and planar thermal Hall set‐ups is discussed. [ABSTRACT FROM AUTHOR]

Topological materials are currently considered excellent catalysts for heterogeneous processes because of their surface metallic states and excellent carrier mobility. This work will show that cubic palladium bronze LaPd3S4 is an ideal topological material with multifold fermions, Fermi arcs on the (001) surface, and high catalytic performance for electrochemical hydrogen evolution reactions (HER). A direct correlation has been discovered between the position of the multifold fermions (related to the Fermi level) and Gibbs free energy (ΔGH*). Moreover, by applying the vertical electric field and uniaxial strain to the LaPd3S4, the multifold fermions disappear, and the |ΔGH*| increases, weakening the HER activity. This correlation establishes a clear connection between increased catalytic performance and topological states and fully elucidates the underlying process in topological catalysis. [ABSTRACT FROM AUTHOR]

Heusler compounds belong to a large family of materials and exhibit numerous physical phenomena with promising applications, particularly ferromagnetic Weyl semimetals for their use in spintronics and memory devices. Here, anomalous Hall transport is reported in the room‐temperature ferromagnets NiMnSb (half‐metal with a Curie temperature (TC) of 660 K) and PtMnSb (pseudo half‐metal with a TC of 560 K). They exhibit 4 µB/f.u. magnetic moments and non‐trivial topological states. Moreover, NiMnSb and PtMnSb are the first half‐Heusler ferromagnets to be reported as Weyl semimetals, and they exhibit anomalous Hall conductivity (AHC) due to the extended tail of the Berry curvature in these systems. The experimentally measured AHC values at 2 K are 1.8 × 102 Ω−1 cm−1 for NiMnSb and 2.2 × 103 Ω−1 cm−1 for PtMnSb. The comparatively large value between them can be explained in terms of the spin‐orbit coupling strength. The combined approach of using ab initio calculations and a simple model shows that the Weyl nodes located far from the Fermi energy act as the driving mechanism for the intrinsic AHC. This contribution of topological features at higher energies can be generalized. [ABSTRACT FROM AUTHOR]

The recent discovery of anti‐chiral edge states in magnetic semimetals linking two unequal‐frequency bulk Dirac nodes manifests a paradoxical picture in contrast to the chiral behavior in Chern insulators, implying an untapped phase may exist. Here, a unique Chern metal, exhibiting a nontrivial Chern number but without a complete bandgap is proposed, and the complete topological phase diagram in the modified Haldane model is obtained. Subsequently, the Chern metal in a 2D honeycomb‐lattice gyromagnetic photonic crystal by simultaneously breaking parity and time‐reversal symmetries with opposite and unequal magnetic biases at different sublattices is realized. For the paired complementary‐shape boundaries, such as zigzag/bearded, it is experimentally revealed that either clockwise or counter‐clockwise chiral character is switchable in Chern metals relying on different boundary choices, a remarkable property deemed as bi‐chiral edge propagation. The topological Chern metal with hidden bulk‐boundary correspondence is articulated to bridge the chiral and anti‐chiral paradox gap between Chern insulators and magnetic semimetals. These results enrich the family of Chern materials and highlight the previously untapped on‐demand control of topological edge states. [ABSTRACT FROM AUTHOR]

Ultra‐broadband photodetectors based on semimetal crystals have recently become popular because of their gapless band structures. In particular, semimetal crystals have large carrier mobility or high Seebeck coefficient; this almost eliminates the possibility of using semimetal crystals as photodetectors. In addition, a larger temperature gradient can cause photocurrent generation based on the photothermoelectric effect. Surprisingly, the TaTe2 crystal has a huge absorption coefficient (≈104 cm−1), a minimal specific heat (≈0.172 J g−1 K−1), and a low thermal conductivity (0.3 W m−1 K−1), which is beneficial for generating a high photothermal conversion efficiency of 30.2%, despite its small Seebeck coefficient, and achieving a large temperature gradient occurs for the heat generated by external illumination. Herein, the possibility of photoresponse based on the TaTe2 detector is explored, which has a low carrier mobility (≈10 cm2 V−1 s−1) and a small Seebeck coefficient (≈7.1 µV K−1). The self‐powered TaTe2 photodetector can also provide a competitive photoresponse range from 355 to 2715 nm and exhibit a maximum responsivity of 1.1 mA W−1 with a detectivity of 4.7 × 108 Jones at 455 nm. This study provides a new design scheme and operating mechanism for semimetal photodetectors and enriches semimetal crystal photodetectors. [ABSTRACT FROM AUTHOR]

In graphene on transition metal dichalcogenides, two types of spin–orbit coupling (SOC)—Rashba and spin–valley Zeeman SOCs—can coexist that modify graphene's electronic band differently. Herein, it is shown that the Landau levels (LLs) are also affected by these SOCs distinctively enough to estimate their relative strengths from the Landau fan diagram. A simple theoretical model is used to calculate the LL spectra of graphene for different SOC strengths, revealing that when the total SOC is strong enough (i.e., when it is comparable to the half of the energy gap between the LLs of an intrinsic graphene), the corresponding LLs will split and cross with others depending sensitively on the relative strengths of the SOC terms. To demonstrate how one can use it to estimate the relative SOC strengths, the four key features that are well separated from the complex background are first identified and compared with experiment to show that in the sample investigated, the Rashba SOC is stronger than the spin–valley Zeeman SOC consistent with other spectroscopic measurements. The study therefore provides a simple and practical strategy to analyze the LL spectrum in graphene with SOC before carrying out more in‐depth measurements. [ABSTRACT FROM AUTHOR]

The USEPA issued the "Framework for Metal Risk Assessment" in 2007, recognizing that human and environmental exposure to metals and metalloids (MMEs) poses challenges risk assessment. Inhalation of aerosols containing MMEs is a primary pathway for exposure in the occupational setting, for consumer exposure, and to general population exposure associated with point‐source emissions or ambient sources. The impacts of inhalation can be at the point of deposition (local exposure) or may manifest after uptake into the body (systemic exposure). Both local and systemic exposure can vary with factors that determine the regional deposition of MME‐containing aerosols. Aerosol characteristics such as particle size combine with species‐specific characteristics of airway morphology and lung function to modulate the deposition and clearance of MME particulates. In contrast to oral exposure, often monitored by measuring MME levels in blood or urine, inhalation exposure can produce local pulmonary impacts in the absence of significant systemic distribution. Exposure assessment for nutritionally essential MMEs can be further complicated by homeostatic controls that regulate systemic MME levels. Predictions of local exposure can be facilitated by computer models that estimate regional patterns of aerosol deposition, permitting calculation of exposure intensity in different regions of the respiratory tract. The utility of deposition modeling has been demonstrated in assessments of nutritionally essential MMEs regulated by homeostatic controls and in the comparison of results from inhalation studies in experimental animals. This facilitates extrapolation from animal data to humans and comparisons of exposures possessing mechanistic linkages to pulmonary toxicity and carcinogenesis. Pulmonary deposition models have significantly advanced and have been applied by USEPA in evaluations of particulate matter. However, regional deposition modeling has yet to be incorporated into the general guidance offered by the agency for evaluating inhalation exposure. Integr Environ Assess Manag 2024;20:952–964. © 2023 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC). Key Points: The USEPA is urged to promote the application of models for regional deposition in assessing impacts of inhalation exposure to metal and metalloid particulate matter.The local and systemic impacts of inhaled metals and metalloids are determined by patterns of regional deposition in the respiratory tract. [ABSTRACT FROM AUTHOR]

Topological insulators generally have dielectric bulk and conductive surface states. Consequently, some of these materials are shown to support polaritonic modes at visible and THz frequencies. At the same time, the optical properties of topological insulators in the mid‐infrared (mid‐IR) remain poorly investigated. Here, near‐field imaging is employed to probe the mid‐IR response from the exfoliated flakes of bismuth (Bi)/selenide (Se)/telluride (Te)/antimony (Sb) crystals with varying stoichiometry – Bi2Se3, Bi2Te2Se, and Bi1.5Sb0.5Te1.7Se1.3 – in pristine form as well as covered by thin flakes of hexagonal boron nitride (hBN) is employed. Contrary to theoretical expectations, all three materials exhibit a dielectric response with a high refractive index and with a loss below the experimental detection limit. Particularly, the near‐field mapping of propagating phonon‐polaritons in hBN demonstrates that all three van der Waals crystals with different stoichiometry act as a practically lossless dielectric substrate with an ultra‐high refractive index of up to 7.5 in Bi2Te2Se. Such a unique dielectric crystal will be of great advantage for numerous nanophotonic applications in the mid‐IR. [ABSTRACT FROM AUTHOR]

Two‐dimensional Materials (2DMs) offer significant promise for advancing device miniaturization and extending Moore's law. Despite the challenges posed by high contact resistance in transistors, recent discoveries highlight semimetals as an effective approach for achieving ohmic contact with near‐quantum‐limit contact resistance. The energy band hybridization between semimetal and MoS2 is found to create degenerate states and heavily doped contact, which is proposed as the underlying mechanism responsible for reducing contact resistance. However, a quantitative and comprehensive characterization of the semimetal‐MoS2 interface is lacking, leaving the physical interactions elusive. This study reveals that semimetals induce n‐type doping and tensile strain in monolayer MoS2 grown using CVD, which serve as the contact resistance and mobility boosters. Among the semimetals investigated, including Bismuth (Bi), Antimony (Sb), and their alloy, Bi results in the highest electron doping of 2 × 1013 cm−2 and a 0.5% tensile strain, leading to reduced contact resistance and enhanced mobility. First‐principles calculations and spectroscopy measurements unveil the impact of electron doping and strain in MoS2, and the thermal effects are subsequently explored. This research underscores the potential of semimetals in boosting device performance and lays the foundation for reducing contact resistance in transistors made from 2D materials. [ABSTRACT FROM AUTHOR]

Metals and metalloids (hereafter, metal(loid)s) in plant‐based foods are a source of exposure to humans, but not all metal(loid)‐food interactions are the same. Differences exist between metal(loid)s in terms of their behavior in soils and in how they are taken up by plants and stored in the edible plant tissue/food. Thus, there cannot be one consistent solution to reducing toxic metal(loid)s exposure to humans from foods. In addition, how metal(loid)s are absorbed, distributed, metabolized, and excreted by the human body differs based on both the metal(loid), other elements and nutrients in the food, and the nutritional status of the human. Initiatives like the United States Food and Drug Administration's Closer to Zero initiative to reduce the exposure of young children to the toxic elements cadmium, lead, arsenic, and mercury from foods warrant careful consideration of each metal(loid) and plant interaction. This review explores such plant‐metal(loid) interactions using the example of spinach and the metals cadmium and lead. This review highlights differences in the magnitude of exposure, bioavailability, and the practicality of mitigation strategies while outlining research gaps and future needs. A focus on feasibility and producer needs, informed via stakeholder interviews, emphasizes the need for better analytical testing facilities and grower and consumer education. More research should focus on minimization of chloride inputs for leafy greens to lessen plant‐availability of Cd and the role of oxalate in reducing Cd bioavailability from spinach. These findings are applicable to other leafy greens (e.g., kale, lettuce), but not for other plants or metal(loid)s. Plain Language Summary: Toxic metals like cadmium and lead in foods can be harmful to our health, especially for babies and young children who are more vulnerable due to their smaller size and rapid development. Leafy greens like spinach can absorb these metals from the soil but in different ways. In addition, how and where they accumulate in edible plant tissues also differs. This review uses spinach as an example to compare and contrast how cadmium and lead differ in how they move through soil and accumulate in plant foods. It also discusses practical pre‐ and post‐harvest techniques to lessen human exposure to these metals that can be adopted by producers and consumers. Finally, it highlights future needs and research directions. Key Points: The toxic elements targeted in the Food and Drug Administration Closer to Zero action plan behave differently in soils and in plant uptakeMitigation strategies to reduce exposure to toxic elements must consider the drivers of soil mobility and accumulation into edible tissuesHealth and nutrition factors that affect metal and metalloid bioavailability upon ingestion should also be considered [ABSTRACT FROM AUTHOR]

In contrast to its behavior in solution, the adduct [(LiBr)(tBu)(Ph)Bpin]− (pin=pinacol) transfers its phenyl anion from boron to lithium upon fragmentation in the gas phase. Quantum chemical calculations predict this exceptional transmetalation to be exothermic relative to the separated reactants, [(tBu)(Ph)Bpin]− and LiBr, which we attribute to the high phenyl‐anion affinity of the coordinatively unsaturated LiBr unit. The addition of a single molecule of tetrahydrofuran drastically reduces the phenyl‐anion affinity of LiBr and thereby renders the transmetalation from boron to lithium endothermic. Thus, the probed system highlights the importance of solvation and ligation effects in transmetalations. For correctly predicting the direction, in which these reactions proceed, it is not sufficient to consider the electronegativities or partial charges of the involved metals or metalloids. Instead, the individual coordination states and their changes over the course of the reaction must be taken into account. [ABSTRACT FROM AUTHOR]

We have used density functional theory simulations to explore the topological characteristics of a new MXene‐like material, V4C3, and its oxide counterpart, assessing their potential as anode materials for Mg‐ion batteries. Our research reveals that V4C3 monolayer is a topological type‐II nodal line semimetal, protected by time reversal and spatial inversion symmetries. This type‐II nodal line is marked by unique drumhead‐like edge states that appear either inside or outside the loop circle, contingent upon the edge ending. Intriguingly, even with an increase in metallicity due to oxygen functionalization, the topological features of V4C3 remain intact. Consequently, the monolayer V4C3 has a topologically enhanced electrical conductivity that amplifies further upon oxygen functionalization. During the charging phase, a remarkable storage concentration led to a peak specific capacity of 894.73 mAh g−1 for V4C3, which only decreases to 789.33 mAh g−1 for V4C3O2. When compared to V2C, V4C3 displays a significantly lower specific capacity loss due to functionalization, demonstrating its superior electrochemical properties. Additionally, V4C3 and V4C3O2 exhibit moderate average open‐circuit voltages (0.54 V for V4C3 and 0.58 V for V4C3O2) and energy barriers for intercalation migration (ranging between 0.29–0.63 eV), which are desirable for anode materials. Thus, our simulation results support V4C3 potential as an efficient anode material for Mg‐ion batteries. [ABSTRACT FROM AUTHOR]

In recent years, 3D Dirac semimetals (DSM) with linear energy‐momentum dispersion near the Fermi points have emerged as promising material candidates for novel tunable metamaterial devices due to their prominent electromagnetic performance and excellent tunability. In this work, the propagation characteristics of 3D DSM‐supported double and triple stripe patterned metamaterial absorbers (MMAs) are investigated in the terahertz (THz) regime by facile modulation of the Fermi level. The results manifest that for the double stripe patterned devices, two strong absorption peaks with near unity are observed at 0.97 THz and 1.63 THz, respectively. When the Fermi level varies in the range of 0.01–0.15 eV, the amplitude (frequency) modulation depth of resonance is up to 77% (27.3%). Additionally, triple stripe MMAs supported by 3D DSM are devised, which can achieve resonant absorption peaks at three specific frequencies of 0.23, 0.345, and 0.46 THz, while the amplitudes of the peaks are as high as 0.997, 0.940, and 0.779, respectively. Furthermore, the resonances can also be regulated, and the amplitude MD reaches ≈20%. These results are very helpful in understanding the tuning mechanisms of metamaterial devices and aiding the design of THz functional devices, such as receivers, detectors, and modulators. [ABSTRACT FROM AUTHOR]

Infrared (IR) detection is vital for various military and civilian applications. Recent research has highlighted the potential of two‐dimensional (2D) topological semimetals in IR detection due to their distinctive advantages, including van der Waals (vdW) stacking, gapless electronic structure, and Van Hove singularities in the electronic density of states. However, challenges such as large‐scale patterning, poor photoresponsivity, and high dark current of photodetectors based on 2D topological semimetals significantly impede their wider applications in low‐energy photon sensing. Here, we demonstrate the in situ fabrication of PtSe2/Ge Schottky junction by directly depositing 2D PtSe2 films with a vertical layer structure on a Ge substrate with an ultrathin AlOx layer. Due to high quality junction, the photodetector features a broadband response of up to 4.6 μm, along with a high specific detectivity of ~1012 Jones, and operates with remarkable stability in ambient conditions as well. Moreover, the highly integrated device arrays based on PtSe2/AlOx/Ge Schottky junction showcases excellent Mid‐IR (MIR) imaging capability at room temperature. These findings highlight the promising prospects of 2D topological semimetals for uncooled IR photodetection and imaging applications. [ABSTRACT FROM AUTHOR]

In this work a hybrid nanoplasmonic‐Weyl Semimetal (WSM) structure is realized for the first time utilizing silver nanopatch antennas and WSM Tantalum Arsenide (TaAs). The studied hybrid WSM‐nanoplasmonic structure demonstrated a substantial, over x4.5 enhancement of the second harmonic generation (SHG) process compared to a bare TaAs film. To realize the hybrid structure while preserving TaAs properties, a scalable, non‐destructive manufacturing approach is developed that involves the fabrication of TaAs flakes from single crystalline TaAs, overgrowth of a silicon nitride overlayer, and drop‐casting of silver nanopatch antennas. The strong polarization response of both the bare flakes, along with the hybrid‐nanoplasmonic cavities demonstrates that this approach uniquely preserves the TaAs crystal structure and its optical response while providing significant enhancement of the nonlinear properties. The developed method allows leveraging the capabilities of plasmonics to control and enhance light‐matter interactions at the nanometer scale to access and engineer WSM response. This work is the first step towards high‐performance nanophotonic devices utilizing WSM topological properties. [ABSTRACT FROM AUTHOR]

Topological insulators have recently received attention in optoelectronic devices because of their high mobility and broadband absorption resulting from their topological surface states. In particular, theoretical and experimental studies have emerged that can improve the spin generation efficiency in a topological insulator‐based p–n junction structure called a TPNJ, drawing attention in optospintronics. Recently, research on implementing the TPNJ structure is conducted; however, studies on the device characteristics of the TPNJ structure are still insufficient. In this study, the TPNJ structure is effectively implemented without intermixing by controlling the annealing temperature, and the photocharacteristics appearing in the TPNJ structure are investigated using a cross‐pattern that can compare the characteristics in a single device. Enhanced photo characteristics are observed for the TPNJ structure. An optical pump Terahertz probe and a physical property measurement system are used to confirm the cause of improved photoresponsivity. Consequently, the photocharacteristics are improved owing to the change in the absorption mechanism and surface transport channel caused by the Fermi level shift in the TPNJ structure. [ABSTRACT FROM AUTHOR]

The emergence of novel topological semimetal materials, accompanied by exotic non‐equilibrium properties, not only provides a fertile playground for a fundamental level of interest but also opens exciting opportunities for inventing new applications by making use of different light‐induced effects such as nonlinear optics, optoelectronics, especially for the highly pursued terahertz (THz) technology due to the gapless electronic structures. Exploring type‐II Weyl semimetal endowed with the richness of quantum wavefunction and peculiar band structure, underlie strong nonlinear coupling with THz waves. Here, the selective growth of type‐II Weyl semimetal NbIrTe4 by means of a self‐flux approach is reported, which hosts strongly tilted Weyl cones and exotic Fermi arcs. The oscillating THz field induced by the antenna is engineered in terms of planar metal‐topological semimetal‐metal structure, along with van der Waals stacking, which allows for self‐powered photodetection at room temperature. The results elucidate the superior performance of NbIrTe4‐graphene heterostructure‐based photodetectors with responsivity up to 264.6 V W−1 at 0.30 THz, fast response of 1 µs as well as low noise equivalent power ˂0.28 nW Hz−0.5 is achieved, already exhibiting high‐quality imaging at THz frequency. The results promise superb impacts in exploring topological Weyl semimetals for efficient low‐energy photon harvesting. [ABSTRACT FROM AUTHOR]

Due to anthropogenic activities, environmental pollution of heavy metals/metalloids (HMs) has increased and received growing attention in recent decades. Plants growing in HM-contaminated soils have slower growth and development, resulting in lower agricultural yield. Exposure to HMs leads to the generation of free radicals (oxidative stress), which alters plant morpho-physiological and biochemical pathways at the cellular and tissue levels. Plants have evolved complex defense mechanisms to avoid or tolerate the toxic effects of HMs, including HMs absorption and accumulation in cell organelles, immobilization by forming complexes with organic chelates, extraction via numerous transporters, ion channels, signaling cascades, and transcription elements, among others. Nonetheless, these internal defensive mechanisms are insufficient to overcome HMs toxicity. Therefore, unveiling HMs adaptation and tolerance mechanisms is necessary for sustainable agriculture. Recent breakthroughs in cutting-edge approaches such as phytohormone and gasotransmitters application, nanotechnology, omics, and genetic engineering tools have identified molecular regulators linked to HMs tolerance, which may be applied to generate HMs-tolerant future plants. This review summarizes numerous systems that plants have adapted to resist HMs toxicity, such as physiological, biochemical, and molecular responses. Diverse adaptation strategies have also been comprehensively presented to advance plant resilience to HMs toxicity that could enable sustainable agricultural production. [ABSTRACT FROM AUTHOR]

Topological superconductors have drawn significant interest from the scientific community due to the accompanying Majorana fermions. Here, the discovery of electronic structure and superconductivity (SC) in high‐entropy ceramics Ti0.2Zr0.2Nb0.2Mo0.2Ta0.2Cx (x = 1 and 0.8) combined with experiments and first‐principles calculations is reported. The Ti0.2Zr0.2Nb0.2Mo0.2Ta0.2Cx high‐entropy ceramics show bulk type‐II SC with Tc ≈ 4.00 K (x = 1) and 2.65 K (x = 0.8), respectively. The specific heat jump (∆C/γTc) is equal to 1.45 (x = 1) and 1.52 (x = 0.8), close to the expected value of 1.43 for the BCS superconductor in the weak coupling limit. The high‐pressure resistance measurements show a robust SC against high physical pressure in Ti0.2Zr0.2Nb0.2Mo0.2Ta0.2C, with a slight Tc variation of 0.3 K within 82.5 GPa. Furthermore, the first‐principles calculations indicate that the Dirac‐like point exists in the electronic band structures of Ti0.2Zr0.2Nb0.2Mo0.2Ta0.2C, which is potentially a topological superconductor. The Dirac‐like point is mainly contributed by the d orbitals of transition metals M and the p orbitals of C. The high‐entropy ceramics provide an excellent platform for the fabrication of novel quantum devices, and the study may spark significant future physics investigations in this intriguing material. [ABSTRACT FROM AUTHOR]

Recent progress in growth techniques has enabled the fabrication of stacks of transition metal dichalcogenide monolayers combined with different nanostructures ranging from other 2D layers over dye molecules to even plasmonic nanoparticles. Such structures promise to combine the optoelectric properties of the constituents allowing to design structures with desired properties. For all of these examples, a detailed knowledge of the coupling among different constituents is crucial. In this article, a unified description is presented based on Maxwell Bloch equations to describe dipolar interactions among different types of heterostructures. Exemplary, Förster‐type energy transfer from dye molecules to MoS2 monolayers, strong coupling at MoSe2–metal nanoparticle interfaces, Meitner–Auger‐like interlayer coupling in WSe2–graphene stacks, and relaxation processes of hot interlayer excitons in MoSe2–WSe2 heterobilayers are discussed. [ABSTRACT FROM AUTHOR]

Alteration of wet and dry periods affects soil geochemical properties that drive contaminant availability and mobility. Consequently, the efficiency of soil remediation may vary, and thus soil management needs to consider these variations. This study reveals the effect of soil moisture manipulation on the behaviour of the toxic metalloids antimony (Sb) and arsenic (As) and the immobilisation efficiency of nanoscale zero-valent iron (nZVI), biochar (BC) and BC modified by iron or iron/ferrous sulphide (nZVI-BC and Fe/FeS-BC). Soil samples from an abandoned Sb mining site were tested under laboratory conditions. Two distinct (organic and mineral) soil layers were incubated with each of the amendments (2% w/w application rate) at 50% and 100% water holding capacity (WHC) of the soils for 10 weeks, and subsequently extracted with demineralised water and rainwater. The immobilisation efficiency of the tested amendments was significantly influenced by the different soil moisture regimes and type of contaminant. Sorption onto secondary Fe minerals was the dominant Sb/As immobilizing mechanism. The iron-based amendments showed up to 97% efficiency for Sb and up to 96% for As. However, Sb/As release was generally higher at 100% WHC and in the rainwater extracts compared to the other conditions, indicating that heavy rainfall and flooding of soils in-situ may increase contaminant availability and mobility. In the organic layer, enhanced formation and leaching of metalloid-DOC complexes and sorption competition of the negatively charged Sb/As species and DOC can be expected. Also, reductive dissolution of Sb or As-bearing metal oxides could lead to the observed higher Sb/As release under flooded conditions, resulting in exacerbated environmental and health risks. Therefore, it is crucial to (1) improve the sorption characteristics of the tested amendments and/or develop other effective amendments for Sb/As immobilisation in different water regimes in soil; (2) test the amendments under real field conditions to evaluate the long term wet/dry exposure; and (3) develop proper risk assessment and soil remediation strategy for the study area and similar sites. [ABSTRACT FROM AUTHOR]

In southern Africa, the Okavango Delta is a large alluvial fan sustaining a unique wetlands ecosystem in the heart of the Kalahari desert. The Delta is fed by an annual flood that brings water from the Angolan plateaus to the north, down to the Okavango region. The fan is characterized by vegetated, permanent or seasonal floodplains, dotted with thousands of sandy islands of various origin (inverted paleo‐channels, paleo‐dunes, meander bars, etc). On at least some of these islands, shallow groundwater is characterized by a high pH (>8) and a high concentration of metals and metalloids, making it naturally toxic. In the 1990s, McCarthy and co‐workers explain the chemistry of that water through an evapotranspiration model, the flood‐water being pumped by the vegetation toward the center of the islands and progressively enriched in elements by evapotranspiration. This model has been widely applied to all islands in the Okavango, not considering their individual specificities nor that of the surrounding floodplain. Our work, based on a multidisciplinary approach including sedimentology, mineralogy and geochemistry, and discussed by McCarthy and Humphries, questions the established model suggesting that the alkaline water cannot derive from simple concentration of the floodwater. Key Points: The chemical composition of the alkaline groundwater cannot reflect simple evaporation processesThe variable origin of islands in the Okavango Delta makes for variable bio‐geochemical processesThe hydro‐geochemical functioning of the Delta will only be understood through interdisciplinary studies [ABSTRACT FROM AUTHOR]

The rupture of the Fundão dam in Brazil released tons of mining tailings into the Doce River Basin (DRB). This investigation aimed to determine the bioaccumulation of metals in soft tissues of the bivalve Corbicula fluminea exposed to sediments collected in the DRB in four periods (just after, 1, 3, and 3.5 years after the dam rupture). In the exposure bioassays, the concentrations of Al, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn in sediments and bivalve soft tissues were quantified. The concentration of some elements (As, Cd, Mn, and Al) in sediments exceeded the federal limits or regional backgrounds at some sampling sites, but their concentrations tended to decrease over time. However, higher concentrations of many elements were detected in the winter of 2019. Several elements were detected in C. fluminea soft tissues, but the bioaccumulation factors were generally low or not related to those elements associated with the ore tailings, evidencing that the bioavailability of metals to bivalves, in laboratory conditions, was limited. Integr Environ Assess Manag 2024;20:87–98. © 2023 SETAC Key Points: The bivalve Corbicula fluminea exposed to sediments collected in the Rio Doce after the Fundão dam failure generally showed low bioaccumulation of metals, as evidenced by the low bioaccumulation factors; some bioaccumulated elements, such as Cu, were not related to the ore tailings.The concentrations of metals and As were high after the dam rupture, and the levels of As, Cd, Mn, and Al in sediments exceeded the federal limits or regional backgrounds at some sampling sites, but their levels tended to decrease over time.The concentrations of metals and As in soft tissues of C. fluminea did not correlate with the respective levels in the sediments, suggesting limited bioavailability of metals or the organisms' ability to cope with metals and metalloids. [ABSTRACT FROM AUTHOR]

Metal–insulator transition has long been one of the key subjects in condensed matter systems. Herein, the emergence of a large energy gap (Eg, 0.8–1.0 eV) in Bi(110) two‐atomic‐layer nanoribbons grown on a SnSe(001) substrate is reported, which normally has an intrinsic semimetal‐like characteristic. The existence of this abnormally large Eg in Bi(110) is, however, determined by Bi coverage. When coverage is above ≈64 ± 2%, Eg vanishes, and instead, a Bi(110) semimetal‐like phase appears through a singular insulator–metal transition. Measurements using qPlus atomic force microscopy demonstrate that either insulating or semimetal‐like Bi(110) possesses a distorted black phosphorous structure with noticeable atomic buckling. Density function theory fully reproduces the semimetal‐like Bi(110) on SnSe(001). However, none of the insulating phases with this large Eg could be traced. Although the underlying mechanism of the large Eg and the insulator‐metal transition requires further exploration, experiments demonstrate that similar results can be achieved for Bi grown on SnS, the structural analog of SnSe, exhibiting an even larger Eg of ≈2.3 eV. The experimental strategy may be generalized to utilization of group‐IV monochalcogenides to create Bi(110) nanostructures with properties unachievable on other surfaces, providing an intriguing platform for exploring the interesting quantum electronic phases. [ABSTRACT FROM AUTHOR]

Novel quantum materials have broad application prospects in spintronic devices and low‐power‐consumption devices. The kagome‐type lattice has special corner‐sharing triangle geometry, providing a rich platform to investigate the relationship of novel correlated topological states, geometry, and strong electron interactions. However, the orbital hybridization in the presence of flat band that originated from the electron localization due to the unique kagome lattice configuration is still unclear. Resonant‐angle‐resolved photoemission spectroscopy is utilized to study the valence band structures of a new vanadium‐based kagome material GdV6Sn6, combined with density functional theory calculation. Herein, a significant hybridization between V 3d and Sn 5p electrons, which paves the way to understand the formation of long‐range magnetic ordering of GdV6Sn6 and other kagome materials at low temperature, is unambiguously revealed in the results. [ABSTRACT FROM AUTHOR]

Electromagnetic field manipulation plays a key role in applications such as electron acceleration, nonlinear light–matter interaction, and radiation engineering. Nonreciprocal materials, such as Weyl semimetals, enable the manipulation of the electromagnetic field in a full photonic manner, owing to their intrinsic time‐reversal symmetry breaking, leading to asymmetric material response for photons with +k$+ k$ and −k$- k$ momenta. Herein, the results suggest that a simple planar interface between semi‐infinite air and a nonreciprocal material can achieve spatiotemporal manipulation of the electromagnetic field. In particular, this work presents three compelling scenarios for electromagnetic wave manipulation: radiation pattern redistribution (with closed‐form expressions provided), carrier‐envelope‐phase control, and spatial profile control. The presented results pave the way for electromagnetic field manipulation using pattern‐free nonreciprocal materials. [ABSTRACT FROM AUTHOR]

Designing novel single‐atom catalysts (SACs) supports to modulate the electronic structure is crucial to optimize the catalytic activity, but rather challenging. Herein, a general strategy is proposed to utilize the metalloid properties of supports to trap and stabilize single‐atoms with low‐valence states. A series of single‐atoms supported on the surface of tungsten carbide (M‐WCx, M=Ru, Ir, Pd) are rationally developed through a facile pyrolysis method. Benefiting from the metalloid properties of WCx, the single‐atoms exhibit weak coordination with surface W and C atoms, resulting in the formation of low‐valence active centers similar to metals. The unique metal‐metal interaction effectively stabilizes the low‐valence single atoms on the WCx surface and improves the electronic orbital energy level distribution of the active sites. As expected, the representative Ru‐WCx exhibits superior mass activities of 7.84 and 62.52 A mgRu−1 for the hydrogen oxidation and evolution reactions (HOR/HER), respectively. In‐depth mechanistic analysis demonstrates that an ideal dual‐sites cooperative mechanism achieves a suitable adsorption balance of Had and OHad, resulting in an energetically favorable Volmer step. This work offers new guidance for the precise construction of highly active SACs. [ABSTRACT FROM AUTHOR]

Tunability of topological photonic structures opens a new avenue for photonics research. The rich physical characteristics of the topological photonics have great significance in practical implementations. In this paper, multi‐type topological states are demonstrated in higher‐order photonic topological insulators based on Kagome metal lattices. By stretching or rotating Kagome metal lattices, two types of topological insulators are obtained, and multi‐type topological states are observed. By stretching Kagome metal lattices, a 1D topological edge state and two types of higher‐order topological corner states (corresponding to a traditional higher‐order topological corner state based on nearest‐neighbor coupling and a new higher‐order corner state caused by long‐range interactions) are obtained in a classical quantization of dipole moments higher‐order topological insulators. By rotating Kagome metal lattices, dual‐band higher‐order valley‐Hall topological insulators are achieved with nodal ring degeneracy. Odd‐type and even‐type topological states are obtained. Achieving reconfigurable, multi‐type, and multi‐band topological insulators by using a single structural unit provides interesting insights into topological photonics and provides an unconventional approach to explore photonic systems and condensed matter physics. [ABSTRACT FROM AUTHOR]

Herein, the density functional theory is used to study the structural, mechanical, electrical, optical, and hydrogen evolution reaction (HER) properties of monolayer structures (α,β)–S2C2N2$\left(\right. \alpha , \beta \left.\right) – \left(\text{S}\right)_{2} \left(\text{C}\right)_{2} \left(\text{N}\right)_{2}$ and (α,β)–SCN/CN$\left(\right. \alpha , \beta \left.\right) – \text{SCN} / \text{CN}$. They are claimed to be stable monolayer structures by phonon dispersion and ab initio molecular dynamics (AIMD). Compared to graphene (≈340 N m−1), the (α,β)–SCN/CN$\left(\right. \alpha , \beta \left.\right) – \text{SCN} / \text{CN}$ shows a higher Young's modulus (≈429, 414 N m−1). Moreover, the piezoelectric stress coefficient of α‐SCN/CN$\text{SCN} / \text{CN}$ (d11$d_{11}$=2.65 pm V−1) is comparable with bulk piezoelectric α‐quartz (d11$d_{11}$=2.3 pm V−1). Exciton effect at M point causes redshift and enhancement of light absorption of α‐SCN/CN$\text{SCN} / \text{CN}$ and β–SCN/CN$\beta – \text{SCN} / \text{CN}$. The overpotential of β–SCN/CN$\beta – \text{SCN} / \text{CN}$ is only –0.072 V. Besides, the (α,β)–SCN/CN$\left(\right. \alpha , \beta \left.\right) – \text{SCN} / \text{CN}$ gives a small effective electron mass of about 0.2(m0). It is worth mentioning that the monolayer structures (α,β)–S2C2N2$\left(\right. \alpha , \beta \left.\right) – \left(\text{S}\right)_{2} \left(\text{C}\right)_{2} \left(\text{N}\right)_{2}$ show the semimetal phases. Due to the unique semimetal phase, the absorption of β–S2C2N2$\beta – \left(\text{S}\right)_{2} \left(\text{C}\right)_{2} \left(\text{N}\right)_{2}$ has an excellent performance in the near‐infrared (NIR) region. It can be enhanced at the NIR region and extended to the middle infrared region when applying tensile stress. These results provide more choices for 2D materials in electrocatalysis, piezoelectric sensors, visible light devices, and infrared photodetectors. [ABSTRACT FROM AUTHOR]

Charge transport in metals and semiconductors is often dominated by electron‐impurity and electron–phonon scattering. Coulomb effects could be found in small corrections to the leading behavior, drag effects in specially fabricated samples, compensated semimetals, and hydrodynamic phenomena in ultra‐pure materials. In contrast, electrical resistivity in strongly correlated systems is poorly understood. Understanding the fate of electron–phonon scattering in these materials may offer a route towards future advancements. [ABSTRACT FROM AUTHOR]

High‐entropy ceramics (HECs) are solid solutions of inorganic compounds with one or more Wyckoff sites shared by equal or near‐equal atomic ratios of multi‐principal elements. Material design and property tailoring possibilities emerge from this new class of materials. Herein, the discovery of superconductivity 2.35 K and topological properties in the (Ti0.2Zr0.2Nb0.2Hf0.2Ta0.2)C high‐entropy carbide ceramic (HECC) is reported, which is not observed before in any of the investigated HECC. Density functional theory calculations show that six type‐II Dirac points exist in (Ti0.2Zr0.2Nb0.2Hf0.2Ta0.2)C, which mainly contributed from the t2g orbitals of transition metals and the p orbitals of C. Due to the stability of the structure, robust superconductivity (SC) under pressure in this HEC superconductor is also observed. This study expands the physical properties of HECs, which may become a new material platform for SC research, especially for studying the coupling between SC and topological physics. [ABSTRACT FROM AUTHOR]

Summary: Some plant species tolerate and accumulate high levels of metals or metalloids in their tissues. The elemental defence hypothesis posits that metal(loid) hyperaccumulation by these plants can serve as protection against antagonists. Numerous studies support this hypothesis. In addition, as other plant species, hyperaccumulators synthesise specialised metabolites that can act as organic defences. In principle, the composition and concentration of plant‐specialised metabolites vary pronouncedly not only among species, but also within species and within individuals. This variation is called chemodiversity. Surprisingly, the role of chemodiversity has received little attention in elemental defence. Thus, we advocate that the concept of the elemental defence hypothesis should be extended and linked to the multifunctionality of plant chemodiversity to better understand the eco‐evolutionary dynamics and maintenance of metal(loid) hyperaccumulation. Comprehensive literature studies revealed that both metal(loid)s and specialised metabolites acting as defences are highly diverse in some hyperaccumulators and the biosynthetic pathways of these two types of defences are partly intertwined. Several edaphic‐, population‐, temporal‐ and spatial‐related factors were found to influence metal(loid) diversity, which should be considered in the elemental defence hypothesis. We thus present a novel synthesis and outlook to extend the elemental defence hypothesis in the light of chemodiversity. [ABSTRACT FROM AUTHOR]

Germanene is a two‐dimensional germanium (Ge) analogous of graphene, and its unique topological properties are expected to make it a material for next‐generation electronics. However, no germanene electronic devices have yet been reported. One of the reasons for this is that germanene is easily oxidized in air due to its lack of chemical stability. Therefore, growing germanene at solid interfaces where it is not oxidized is one of the key steps for realizing electronic devices based on germanene. In this study, the behavior of Ge at the solid interface at high temperatures is observed by transmission electron microscopy (TEM). To achieve such in situ heating TEM observation, this work fabricates a graphene/Ge/graphene encapsulated structure. In situ heating TEM experiments reveal that Ge like droplets move and coalesce with other Ge droplets, indicating that Ge remains as a liquid phase between graphene layers at temperatures higher than the Ge melting point. It is also observed that Ge droplets incorporate the surrounding amorphous Ge as Ge nuclei, thereby increasing its size (domain growth). These results indicate that Ge crystals can be grown at the interface of van der Waals materials, which will be important for future germanene growth at solid interfaces. [ABSTRACT FROM AUTHOR]

Topological nodal‐line semimetals have received extensive attention in recent years, and they exhibit a variety of shapes under various crystallographic symmetry protections, including nodal rings, nodal chains, and nodal knots. By using symmetry analysis and an effective force constant model, it is proposed that a class of 2D hourglass nodal nets protected by nonsymmorphic symmetry can exist in the space group P42/ncm, where the glide operations play a crucial role in the formation of the nets. Further effective k⋅p model analysis shows that the connect points of the nets are Dirac points that are forced by the symmetries. Based on first‐principle calculations, it is predicted that this nodal net can be realized in the phonon dispersion of 3D Sn. The Berry phase and nontrivial surface states further support its nontrivial topological characteristics. Herein, the studies expand the nodal structure in the study of nodal line in phononic systems and offer a solid foundation for subsequent experimental investigation on this challenging topological state. [ABSTRACT FROM AUTHOR]

Activation of cuproptosis pathway has been reported to hold great potential in the application of tumor treatment. But the efficacy of cuproptosis seriously limited by the insufficient accumulation in the tumor sites. Therefore, herein based on the strong stabilization effects of the metalloid element selenium (Se) on copper (Cu), a photothermic Cu2‐xSe nanoparticle encapsulated with bioresponsive dimethyl maleic anhydride (DMMA@Cu2‐xSe) as a copper‐carrier to improve the copper accumulation in tumor is constructed, thus achieving cuproptosis‐driven enhancement of thermotherapy. This nanosystem exhibits the enhancement of tumor cellular uptake by a weak acid‐triggered charge‐switching ability. Next step, the exposed Cu2‐xSe is oxidized and releases divalent copper by high‐level oxide. Then, the abundant copper induces more dihydrolipoamide S‐acetyltransferase oligomerization to down‐regulate FDX1 and tricarboxylic acid cycle‐related proteins, which leads to inhibiting aerobic respiration. Cuproptosis‐induced mitochondrial damage further improves thermotherapy by up‐regulating reactive oxygen species (ROS). In addition, the generated ROS also promotes copper release to strengthen cuproptosis, and eventually improves tumor thermotherapy in turn. In general, DMMA@Cu2‐xSe with sequentially triggered copper‐release, efficient cuproptosis, and appropriate photothermal is a self‐enhanced nanoplatform for cuproptosis‐driven enhancement of thermotherapy. [ABSTRACT FROM AUTHOR]

Achieving low contact resistance (RC) is one of the major challenges in producing 2D FETs for future CMOS technology applications. In this work, the electrical characteristics for semimetal (Sb) and normal metal (Ti) contacted MoS2 devices are systematically analyzed as a function of top and bottom gate‐voltages (VTG and VBG). The semimetal contacts not only significantly reduce RC but also induce a strong dependence of RC on VTG, in sharp contrast to Ti contacts that only modulate RC by varying VBG. The anomalous behavior is attributed to the strongly modulated pseudo‐junction resistance (Rjun) by VTG, resulting from weak Fermi level pinning (FLP) of Sb contacts. In contrast, the resistances under both metallic contacts remain unchanged by VTG as metal screens the electric field from the applied VTG. Technology computer aided design simulations further confirm the contribution of VTG to Rjun, which improves overall RC of Sb‐contacted MoS2 devices. Consequently, the Sb contact has a distinctive merit in dual‐gated (DG) device structure, as it greatly reduces RC and enables effective gate control by both VBG and VTG. The results offer new insight into the development of DG 2D FETs with enhanced contact properties realized by using semimetals. [ABSTRACT FROM AUTHOR]

Topological semimetals have attracted flourishing interest as promising candidates for their unique advantages in achieving highly sensitive, low‐energy photodetection with ultrafast operation. Although various semimetals have been explored recently, new semimetals are still being pursued for high‐responsivity photodetectors with broadband response. Here, a pressure‐induced semiconductor–semimetal transition is observed in two‐dimensional wide‐band semiconducting lead iodide (PbI2). The photocurrent under visible light shows abrupt increases by two orders of magnitude at ≈25 GPa, where the crystalline structure transforms from the Pnma to I4/MMM phase. Meanwhile, the responding band expands from visible light to at least the telecom wavelength 1550 nm. The high‐pressure absorption spectra of PbI2 suggest that the electrical band is closed at the transition point, while the charge transport shows that the sample is still not metallic. Through first‐principles calculations, the photocurrent spurt and infrared band response are attributed to the appearance of a semimetal phase at high pressure, which well explains the nonmetallic transport. The prominent drop in lifetime to a few picoseconds in ultrafast spectroscopy under pressure further confirms the semiconductor–semimetal transition in PbI2. Pressure‐induced semimetallization opens a new strategy for designing a high‐performance photodetector with broadband response. [ABSTRACT FROM AUTHOR]

The operation stability of halide perovskite devices is the critical issue that impedes their commercialization. The main reasons are that the ambient H2O molecules can easily deteriorate the perovskites, while the metal electrodes react in different degrees with the perovskites. Herein, one kind of new electrode, the metalloids, is reported, which are much more stable than the conventional noble metals as electrical contacts for halide perovskites. The degradation mechanism of halide perovskites with noble metal electrodes is carefully studied and compared with the metalloid electrodes. It is found that the iodide ions can easily halogenate Cu and Ag in halide perovskites. Although Au is almost not halogenated, it can also decompose the perovskite film. On the contrary, after long‐term storage, the metalloid electrodes remain intact on the perovskite film without any degradation. In addition, the long‐time operation stability of the perovskite devices with metalloid electrodes is much higher than that of noble metals. First‐principles calculations confirm the exceptional stability of the metalloid electrodes.This work explores the ultra‐stable electrodes for halide perovskites, paving the way to the large‐scale deployment of perovskite‐based electronic devices. [ABSTRACT FROM AUTHOR]

This study presents a thorough analysis of the electronic structures of the TaPxAs1−x series of compounds, which are of significant interest due to their potential as topological materials. Using a combination of first principles and Wannier‐based tight‐binding methods, this study investigates both the bulk and surface electronic structures of the compounds for varying compositions (x = 0, 0.25, 0.50, 0.75, 1), with a focus on their topological properties. By using chirality analysis, (111) surface electronic structure analysis, and surface Fermi arcs analysis, it is established that the TaPxAs1−x compounds exhibit topologically nontrivial behavior, characterized as Weyl semimetals (WSMs). The effect of spin–orbit coupling (SOC) on the topological properties of the compounds is further studied. In the absence of SOC, the compounds exhibit linearly dispersive fourfold degenerate points in the first Brillouin zone (FBZ) resembling Dirac semimetals. However, the introduction of SOC induces a phase transition to WSM states, with the number and position of Weyl points (WPs) varying depending on the composition of the alloy. For example, TaP has 12 WPs in the FBZ. The findings provide novel insights into the electronic properties of TaPxAs1−x compounds and their potential implications for the development of topological materials for various technological applications. [ABSTRACT FROM AUTHOR]

The prevalent global energy crisis calls for searching viable pathways for generating green hydrogen as an alternative energy resource. Dye‐sensitized photocatalytic water splitting is a feasible solution to produce green hydrogen. However, identifying suitable catalysts has been one of the bottlenecks in driving dye‐sensitized photocatalysis efficiently. In this work, a new class of electrocatalysts is reported based on the layered Weyl semimetals MIrTe4 (M = Nb, Ta) for the Eosin Y (EY)‐sensitized hydrogen evolution reaction (HER). NbIrTe4 and TaIrTe4 exhibit HER activities of ≈18 000 and 14 000 µmol g−1 respectively, after 10 h of irradiation with visible light. Time‐dependent UV‐Vis spectroscopy and high‐pressure liquid chromatography coupled with mass spectrometry analysis shed light on the reaction dynamics and enable a deeper understanding of the observed trend in hydrogen evolution rates for MIrTe4. MIrTe4 semimetals outperform transition metal‐based Weyl semimetals in terms of catalytic HER activity using EY as photosensitizer and triethanolamine as the sacrificial agent. It is hypothesized that the topology‐related band inversion in MIrTe4 Weyl semimetals promotes a high density of M d‐states near the Fermi level, driving their high catalytic performance. This study introduces a new class of layered Weyl semimetals as efficient catalysts, and provides perspectives for designing topology‐enhanced catalysts. [ABSTRACT FROM AUTHOR]

Temperature‐dependent electronic and magnetic properties are reported for nickel‐deficient NiV2Se4. Single‐crystal X‐ray diffraction shows it to crystallize in the monoclinic Cr3S4 structure type with space group I2/m$I2/m$ and vacancies on the Ni site, resulting in the composition Ni0.85V2Se4 in agreement with our electron‐probe microanalysis. Structural distortions are not observed down to 1.5 K. Nevertheless, the electrical resistivity shows metallic behavior with a broad anomaly around 150–200 K that is also observed in the heat capacity data. This anomaly indicates a change of state of the material below 150 K. It is believed that this anomaly could be due to spin fluctuations or charge‐density‐wave fluctuations, where the lack of long‐range order is caused by vacancies at the Ni site of Ni0.85V2Se4. The non‐linear temperature dependence of the resistivity as well as an enhanced value of the Sommerfeld coefficient γ=104.0(1)$\gamma = 104.0\,(1)$ mJ mol−1 K−2 suggest strong electron–electron correlations in this material. First‐principles calculations performed for NiV2Se4, which are also applicable to Ni0.85V2Se4, classify this material as a topological metal with Z2=(1;110)$Z_2 = (1;110)$ and coexisting electron and hole pockets at the Fermi level. The phonon spectrum lacks any soft phonon mode, consistent with the absence of periodic lattice distortion in the present experiments. [ABSTRACT FROM AUTHOR]

The rational design of a stable and catalytic carbon cathode is crucial for the development of rechargeable lithium‐oxygen (LiO2) batteries. An edge‐site‐free and topological‐defect‐rich graphene‐based material is proposed as a pure carbon cathode that drastically improves LiO2 battery performance, even in the absence of extra catalysts and mediators. The proposed graphene‐based material is synthesized using the advanced template technique coupled with high‐temperature annealing at 1800 °C. The material possesses an edge‐site‐free framework and mesoporosity, which is crucial to achieve excellent electrochemical stability and an ultra‐large capacity (>6700 mAh g−1). Moreover, both experimental and theoretical structural characterization demonstrates the presence of a significant number of topological defects, which are non‐hexagonal carbon rings in the graphene framework. In situ isotopic electrochemical mass spectrometry and theoretical calculations reveal the unique catalysis of topological defects in the formation of amorphous Li2O2, which may be decomposed at low potential (∼ 3.6 V versus Li/Li+) and leads to improved cycle performance. Furthermore, a flexible electrode sheet that excludes organic binders exhibits an extremely long lifetime of up to 307 cycles (>1535 h), in the absence of solid or soluble catalysts. These findings may be used to design robust carbon cathodes for LiO2 batteries. [ABSTRACT FROM AUTHOR]

Temperature‐dependent electronic and magnetic properties are reported for nickel‐deficient NiV2Se4. Single‐crystal X‐ray diffraction shows it to crystallize in the monoclinic Cr3S4 structure type with space group I2/m$I2/m$ and vacancies on the Ni site, resulting in the composition Ni0.85V2Se4 in agreement with our electron‐probe microanalysis. Structural distortions are not observed down to 1.5 K. Nevertheless, the electrical resistivity shows metallic behavior with a broad anomaly around 150–200 K that is also observed in the heat capacity data. This anomaly indicates a change of state of the material below 150 K. It is believed that this anomaly could be due to spin fluctuations or charge‐density‐wave fluctuations, where the lack of long‐range order is caused by vacancies at the Ni site of Ni0.85V2Se4. The non‐linear temperature dependence of the resistivity as well as an enhanced value of the Sommerfeld coefficient γ=104.0(1)$\gamma = 104.0\,(1)$ mJ mol−1 K−2 suggest strong electron–electron correlations in this material. First‐principles calculations performed for NiV2Se4, which are also applicable to Ni0.85V2Se4, classify this material as a topological metal with Z2=(1;110)$Z_2 = (1;110)$ and coexisting electron and hole pockets at the Fermi level. The phonon spectrum lacks any soft phonon mode, consistent with the absence of periodic lattice distortion in the present experiments. [ABSTRACT FROM AUTHOR]