A stable low-temperature H2-production catalyst by crowding Pt on α-MoC.

The water-gas shift (WGS) reaction is an industrially important source of pure hydrogen (H2) at the expense of carbon monoxide and water1,2. This reaction is of interest for fuel-cell applications, but requires WGS catalysts that are durable and highly active at low temperatures3. Here we demonstrate that the structure (Pt1-Ptn)/α-MoC, where isolated platinum atoms (Pt1) and subnanometre platinum clusters (Ptn) are stabilized on α-molybdenum carbide (α-MoC), catalyses the WGS reaction even at 313 kelvin, with a hydrogen-production pathway involving direct carbon monoxide dissociation identified. We find that it is critical to crowd the α-MoC surface with Pt1 and Ptn species, which prevents oxidation of the support that would cause catalyst deactivation, as seen with gold/α-MoC (ref. 4), and gives our system high stability and a high metal-normalized turnover number of 4,300,000 moles of hydrogen per mole of platinum. We anticipate that the strategy demonstrated here will be pivotal for the design of highly active and stable catalysts for effective activation of important molecules such as water and carbon monoxide for energy production.

Aberration Correction for Large-Angle Illumination Scanning Transmission Electron Microscopy by Using Iterative Electron Ptychography Algorithms.

Modern aberration correctors in the scanning transmission electron microscope (STEM) have dramatically improved the attainable spatial resolution and enabled atomical structure and spectroscopic analysis even at low acceleration voltages (≤80 kV). For a large-angle illumination, achieving successful aberration correction to high angles is challenging with an aberration corrector, which limits further improvements in applications such as super-resolution, three-dimensional atomic depth resolution, or atomic surface morphology analyses. Electron ptychography based on four-dimensional STEM can provide a postprocessing strategy to overcome the current technological limitations. In this work, we have demonstrated that aberration correction for large-angle illumination is feasible by pushing the capabilities of regularized ptychographic iterative engine algorithms to reconstruct 4D data sets acquired using a relatively low-efficiency complementary metal oxide semiconductor camera. We report super resolution (0.71 Å) with large-angle illumination (50-60 mrad) and under 60 kV accelerating voltage.

Engineering Interlayer Electron-Phonon Coupling in WS2/BN Heterostructures.

In van der Waals (vdW) heterostructures, the interlayer electron-phonon coupling (EPC) provides one unique channel to nonlocally engineer these elementary particles. However, limited by the stringent occurrence conditions, the efficient engineering of interlayer EPC remains elusive. Here we report a multitier engineering of interlayer EPC in WS2/boron nitride (BN) heterostructures, including isotope enrichments of BN substrates, temperature, and high-pressure tuning. The hyperfine isotope dependence of Raman intensities was unambiguously revealed. In combination with theoretical calculations, we anticipate that WS2/BN supercells could induce Brillouin-zone-folded phonons that contribute to the interlayer coupling, leading to a complex nature of broad Raman peaks. We further demonstrate the significance of a previously unexplored parameter, the interlayer spacing. By varying the temperature and high pressure, we effectively manipulated the strengths of EPC with on/off capabilities, indicating critical thresholds of the layer-layer spacing for activating and strengthening interlayer EPC. Our findings provide new opportunities to engineer vdW heterostructures with controlled interlayer coupling.

Alloying Nickel with Molybdenum Significantly Accelerates Alkaline Hydrogen Electrocatalysis.

Bifunctional hydrogen electrocatalysis (hydrogen-oxidation and hydrogen-evolution reactions) in alkaline solution is desirable but challenging. Among all available electrocatalysts, Ni-based materials are the only non-precious-metal-based candidates for alkaline hydrogen oxidation, but they generally suffer from low activity. Here, we demonstrate that properly alloying Ni with Mo could significantly promote its electrocatalytic performance. Ni4 Mo alloy nanoparticles are prepared from the reduction of molybdate-intercalated Ni(OH)2 nanosheets. The final product exhibits an apparent hydrogen-oxidation activity exceeding that of the Pt benchmark and a record-high mass-specific kinetic current of 79 A g-1 at an overpotential of 50 mV. A superior hydrogen-evolution performance is also measured in alkaline solution. These experimental data are rationalized by our theoretical simulations, which show that alloying Ni with Mo significantly weakens its hydrogen adsorption, improves the hydroxyl adsorption and decreases the reaction barrier for water formation.

Observation of the Kondo Effect in Multilayer Single-Crystalline VTe2 Nanoplates.

We report the chemical vapor deposition (CVD) growth, characterization, and low-temperature magnetotransport of 1T phase multilayer single-crystalline VTe2 nanoplates. The transport studies reveal that no sign of intrinsic long-range ferromagnetism but localized magnetic moments exist in the individual multilayer metallic VTe2 nanoplates. The localized moments give rise to the Kondo effect, evidenced by logarithmical increment of resistivity with decreasing temperature and negative magnetoresistance (NMR) regardless of the direction of magnetic field at temperatures below the resistivity minimum. The low-temperature resistivity upturn is well described by the Hamann equation, and the NMR at different temperatures, a manifestation of the magnetization of the localized spins, is well fitted to a Brillouin function for S = 1/2. Density functional theory calculations reveal that the localized magnetic moments mainly come from the interstitial vanadium ions in the VTe2 nanoplates. Our results will shed light on the study of magnetic properties, strong correlation, and many-body physics in two-dimensional metallic transition metal dichalcogenides.

Design Nitrogen (N) and Sulfur (S) Co-Doped 3D Graphene Network Architectures for High-Performance Sodium Storage.

To develop high-performance sodium-ion batteries (NIBs), electrodes should possess well-defined pathways for efficient electronic/ionic transport. In this work, high-performance NIBs are demonstrated by designing a 3D interconnected porous structure that consists of N, S co-doped 3D porous graphene frameworks (3DPGFs-NS). The most typical electrode materials (i.e., Na3 V2 (PO4 )3 (NVP), MoS2 , and TiO2 ) are anchored onto the 3DPGFs-NS matrix (denoted as NVP@C@3DPGFs-NS; MoS2 @C@3DPGFs-NS and TiO2 @C@3DPGFs-NS) to demonstrate its general process to boost the energy density of NIBs. The N, S co-doped porous graphene structure with a large surface area offers fast ionic transport within the electrode and facilitates efficient electron transport, and thus endows the 3DPGFs-NS-based composite electrodes with excellent sodium storage performance. The resulting NVP@C@3DPGFs-NS displays excellent electrochemical performance as both cathode and anode for NIBs. The MoS2 @C@3DPGFs-NS and TiO2 @C@3DPGFs-NS deliver capacities of 317 mAhg-1 at 5 Ag-1 after 1000 cycles and 185 mAhg-1 at 1 Ag-1 after 2000 cycles, respectively. The excellent long cycle life is attributed to the 3D porous structure that could greatly release mechanical stress from repeated Na+ extraction/insertion. The novel structure 3D PGFs-NS provides a general approach to modify electrodes of NIBs and holds great potential applications in other energy storage fields.

In Situ Atomic-Scale Observation of Electrochemical Delithiation Induced Structure Evolution of LiCoO2 Cathode in a Working All-Solid-State Battery.

We report a method for in situ atomic-scale observation of electrochemical delithiation in a working all-solid-state battery using a state-of-the-art chip based in situ transmission electron microscopy (TEM) holder and focused ion beam milling to prepare an all-solid-state lithium-ion battery sample. A battery consisting of LiCoO2 cathode, LLZO solid state electrolyte and gold anode was constructed, delithiated and observed in an aberration corrected scanning transmission electron microscope at atomic scale. We found that the pristine single crystal LiCoO2 became nanosized polycrystal connected by coherent twin boundaries and antiphase domain boundaries after high voltage delithiation. This is different from liquid electrolyte batteries, where a series of phase transitions take place at LiCoO2 cathode during delithiation. Both grain boundaries become more energy favorable along with extraction of lithium ions through theoretical calculation. We also proposed a lithium migration pathway before and after polycrystallization. This new methodology could stimulate atomic scale in situ scanning/TEM studies of battery materials and provide important mechanistic insight for designing better all-solid-state battery.

Multichannel Porous TiO2 Hollow Nanofibers with Rich Oxygen Vacancies and High Grain Boundary Density Enabling Superior Sodium Storage Performance.

TiO2 as an anode for sodium-ion batteries (NIBs) has attracted much recent attention, but poor cyclability and rate performance remain problematic owing to the intrinsic electronic conductivity and the sluggish diffusivity of Na ions in the TiO2 matrix. Herein, a simple process is demonstrated to improve the sodium storage performance of TiO2 by fabricating a 1D, multichannel, porous binary-phase anatase-TiO2 -rutile-TiO2 composite with oxygen-deficient and high grain-boundary density (denoted as a-TiO2-x /r-TiO2-x ) via electrospinning and subsequent vacuum treatment. The introduction of oxygen vacancies in the TiO2 matrix enables enhanced intrinsic electronic conductivity and fast sodium-ion diffusion kinetics. The porous structure offers easy access of the liquid electrolyte and a short transport path of Na+ through the pores toward the TiO2 nanoparticle. Furthermore, the high density of grain boundaries between the anatase TiO2 and rutile TiO2 offer more interfaces for a novel interfacial storage. The a-TiO2-x /r-TiO2-x shows excellent long cycling stability (134 mAh g-1 at 10 C after 4500 cycles) and superior rate performance (93 mAh g-1 after 4500 cycles at 20 C) for sodium-ion batteries. This simple and effective process could serve as a model for the modification of other materials applied in energy storage systems and other fields.

Precisely Aligned Monolayer MoS2 Epitaxially Grown on h-BN basal Plane.

Control of the precise lattice alignment of monolayer molybdenum disulfide (MoS2 ) on hexagonal boron nitride (h-BN) is important for both fundamental and applied studies of this heterostructure but remains elusive. The growth of precisely aligned MoS2 domains on the basal plane of h-BN by a low-pressure chemical vapor deposition technique is reported. Only relative rotation angles of 0° or 60° between MoS2 and h-BN basal plane are present. Domains with same orientation stitch and form single-crystal, domains with different orientations stitch and from mirror grain boundaries. In this way, the grain boundary is minimized and a continuous film stitched by these two types of domains with only mirror grain boundaries is obtained. This growth strategy is also applicable to other 2D materials growth.

Mott Electrons in an Artificial Graphenelike Crystal of Rare-Earth Nickelate.

Deterministic control over the periodic geometrical arrangement of the constituent atoms is the backbone of the material properties, which, along with the interactions, define the electronic and magnetic ground state. Following this notion, a bilayer of a prototypical rare-earth nickelate, NdNiO_{3}, combined with a dielectric spacer, LaAlO_{3}, has been layered along the pseudocubic [111] direction. The resulting artificial graphenelike Mott crystal with magnetic 3d electrons has antiferromagnetic correlations. In addition, a combination of resonant X-ray linear dichroism measurements and ab initio calculations reveal the presence of an ordered orbital pattern, which is unattainable in either bulk nickelates or nickelate based heterostructures grown along the [001] direction. These findings highlight another promising venue towards designing new quantum many-body states by virtue of geometrical engineering.

Association between interleukin-4 gene intron 3 VNTR polymorphism and cancer risk.

BACKGROUND: Interleukin-4(IL-4) is a critical inflammatory cytokine and has been involved in pathogenesis of cancer. To date, several studies have investigated the association between IL-4 intron 3 variable number of tandem repeats (VNTR) polymorphism and cancer risk in humans; however, the results remain controversial. We performed this meta-analysis to find a more conclusive association between this polymorphism and cancer risk. METHODS: Eight eligible case-control studies were identified through searching electronic databases, including 1583 cases and 1638 controls. Odds ratio (OR) and corresponding 95% confidence interval (CI) were used to estimate the strength of the association. RESULTS: The results of overall analyses indicated that the variant RP2 allele was associated with a decreased cancer risk compared with the RP1 allele (RP2/RP2 vs. RP1/RP1, OR = 0.64, 95% CI = 0.44-0.94; RP2/RP2 vs. RP1/RP1 + RP1/RP2, OR = 0.75, 95% CI = 0.60-0.92; RP2 vs. RP1, OR = 0.72, 95% CI = 0.56-0.92). In subgroup analyses stratified by ethnicity, there was evidence in the Asian population for an association between this polymorphism and cancer risk (RP2/RP2 vs. RP1/RP1 + RP1/RP2, OR = 0.79, 95% CI = 0.63-0.99; RP2 vs. RP1, OR = 0.77, 95% CI = 0.61-0.97). CONCLUSIONS: IL-4 intron 3 VNTR polymorphism could influence the risk of human cancer. Due to the limitations of this meta-analysis, further well-designed and functional researches should be performed to validate our results.

Room­Temperature Antisymmetric Magnetoresistance in van der Waals Ferromagnet Fe3GaTe2 Nanosheets.

Van der Waals (vdW) ferromagnetic materials have emerged as a promising platform for the development of 2D spintronic devices. However, studies to date are restricted to vdW ferromagnetic materials with low Curie temperature (Tc) and small magnetic anisotropy. Here, a chemical vapor transport method is developed to synthesize a high-quality room-temperature ferromagnet, Fe3GaTe2 (c-Fe3GaTe2), which boasts a high Tc = 356 K and large perpendicular magnetic anisotropy. Due to the planar symmetry breaking, an unconventional room-temperature antisymmetric magnetoresistance (MR) is first observed in c-Fe3GaTe2 devices with step features, manifesting as three distinctive states of high, intermediate, and low resistance with the sweeping magnetic field. Moreover, the modulation of the antisymmetric MR is demonstrated by controlling the height of the surface steps. This work provides new routes to achieve magnetic random storage and logic devices by utilizing the room-temperature thickness-controlled antisymmetric MR and further design room-temperature 2D spintronic devices based on the vdW ferromagnet c-Fe3GaTe2.

Water-filtered infrared A radiation hyperthermia combined with immunotherapy for advanced gastrointestinal tumours.

This study pioneered the use of WIRA whole-body infrared hyperthermia combined with ICI therapy to treat GIT and verified the feasibility and safety of HIT. The final results showed a DCR of 55.6%, with a median PFS of 53.5 days, median OS of 134 days, and an irAE incidence of 22.2%. Therefore, we believe that HIT can exert multiple synergistic sensitisation effects, thereby providing clinical benefits to patients with advanced GITs, increasing overall safety, and improving patients' QOL.

INTRODUCTION: This study aimed to validate the effectiveness, safety and feasibility of water­filtered infrared A radiation (WIRA) whole­body hyperthermia combined with immune checkpoint inhibitor (ICI) therapy (HIT) and evaluate the real­world clinical application prospects. METHODS: This open­label single­arm phase 2 clinical trial (NCT06022692) aimed to enrol advanced gastrointestinal tumour (GIT) patients with the MSS/pMMR phenotype. The patients were treated with whole­body hyperthermia on Days 1 and 8 of each HIT cycle along with administration of tislelizumab on Day 2. RESULTS: Between 1 June 2020 and 31 May 2022, 18 patients were enrolled in the study, including those with gastric cancer (n = 6), colon cancer (n = 7), rectal cancer (n = 3) and appendiceal cancer (n = 2). As of 19 May 2023, 17 of the 18 patients had died, including 14 deaths caused by tumour progression and three deaths caused by diseases other than cancer, while one patient was still undergoing follow­up. In terms of efficacy, the median DCR was 55.6%, while the median PFS and OS were 53.5 days and 134 days, respectively. Four patients (22.2%) experienced immune­related adverse events, and none of the patients reported grade 3 or higher irAEs. Hyperthermia was followed by an increase in the number of tumour immune­activated cells. CONCLUSIONS: HIT can provide survival benefits in patients with GITs by activating antitumour immune function and shows good safety and feasibility.

Unprecedentedly high activity and selectivity for hydrogenation of nitroarenes with single atomic Co1-N3P1 sites.

Transition metal single atom catalysts (SACs) with M1-Nx coordination configuration have shown outstanding activity and selectivity for hydrogenation of nitroarenes. Modulating the atomic coordination structure has emerged as a promising strategy to further improve the catalytic performance. Herein, we report an atomic Co1/NPC catalyst with unsymmetrical single Co1-N3P1 sites that displays unprecedentedly high activity and chemoselectivity for hydrogenation of functionalized nitroarenes. Compared to the most popular Co1-N4 coordination, the electron density of Co atom in Co1-N3P1 is increased, which is more favorable for H2 dissociation as verified by kinetic isotope effect and density functional theory calculation results. In nitrobenzene hydrogenation reaction, the as-synthesized Co1-N3P1 SAC exhibits a turnover frequency of 6560 h-1, which is 60-fold higher than that of Co1-N4 SAC and one order of magnitude higher than the state-of-the-art M1-Nx-C SACs in literatures. Furthermore, Co1-N3P1 SAC shows superior selectivity (>99%) toward many substituted nitroarenes with co-existence of other sensitive reducible groups. This work is an excellent example of relationship between catalytic performance and the coordination environment of SACs, and offers a potential practical catalyst for aromatic amine synthesis by hydrogenation of nitroarenes.

Titanium doped kagome superconductor CsV3-xTixSb5 and two distinct phases.

The vanadium-based kagome superconductor CsV3Sb5 has attracted tremendous attention due to its unexcepted anomalous Hall effect (AHE), charge density waves (CDWs), nematicity, and a pseudogap pair density wave (PDW) coexisting with unconventional strong-coupling superconductivity. The origins of CDWs, unconventional superconductivity, and their correlation with different electronic states in this kagome system are of great significance, but so far, are still under debate. Chemical doping in the kagome layer provides one of the most direct ways to reveal the intrinsic physics, but remains unexplored. Here, we report, for the first time, the synthesis of Ti-substituted CsV3Sb5 single crystals and its rich phase diagram mapping the evolution of intertwining electronic states. The Ti atoms directly substitute for V in the kagome layers. CsV3-xTixSb5 shows two distinct superconductivity phases upon substitution. The Ti slightly-substituted phase displays an unconventional V-shaped superconductivity gap, coexisting with weakening CDW, PDW, AHE, and nematicity. The Ti highly-substituted phase has a U-shaped superconductivity gap concomitant with a short-range rotation symmetry breaking CDW, while long-range CDW, twofold symmetry of in-plane resistivity, AHE, and PDW are absent. Furthermore, we also demonstrate the chemical substitution of V atoms with other elements such as Cr and Nb, showing a different modulation on the superconductivity phases and CDWs. These findings open up a way to synthesise a new family of doped CsV3Sb5 materials, and further represent a new platform for tuning the different correlated electronic states and superconducting pairing in kagome superconductors.

Ferritin-based targeted delivery of arsenic to diverse leukaemia types confers strong anti-leukaemia therapeutic effects.

Trivalent arsenic (AsIII) is an effective agent for treating patients with acute promyelocytic leukaemia, but its ionic nature leads to several major limitations like low effective concentrations in leukaemia cells and substantial off-target cytotoxicity, which limits its general application to other types of leukaemia. Here, building from our clinical discovery that cancerous cells from patients with different leukaemia forms featured stable and strong expression of CD71, we designed a ferritin-based As nanomedicine, As@Fn, that bound to leukaemia cells with very high affinity, and efficiently delivered cytotoxic AsIII into a large diversity of leukaemia cell lines and patient cells. Moreover, As@Fn exerted strong anti-leukaemia effects in diverse cell-line-derived xenograft models, as well as in a patient-derived xenograft model, in which it consistently outperformed the gold standard, showing its potential as a precision treatment for a variety of leukaemias.

Atomically sharp interface enabled ultrahigh-speed non-volatile memory devices.

The development of high-performance memory devices has played a key role in the innovation of modern electronics. Non-volatile memory devices have manifested high capacity and mechanical reliability as a mainstream technology; however, their performance has been hampered by low extinction ratio and slow operational speed. Despite substantial efforts to improve these characteristics, typical write times of hundreds of micro- or milliseconds remain a few orders of magnitude longer than that of their volatile counterparts. Here we demonstrate non-volatile, floating-gate memory devices based on van der Waals heterostructures with atomically sharp interfaces between different functional elements, achieving ultrahigh-speed programming/erasing operations in the range of nanoseconds with extinction ratio up to 1010. This enhanced performance enables new device capabilities such as multi-bit storage, thus opening up applications in the realm of modern nanoelectronics and offering future fabrication guidelines for device scale up.

Strain-driven growth of ultra-long two-dimensional nano-channels.

Lateral heterostructures of two-dimensional transition metal dichalcogenides (TMDs) have offered great opportunities in the engineering of monolayer electronics, catalysis and optoelectronics. To explore the full potential of these materials, developing methods to precisely control the spatial scale of the heterostructure region is crucial. Here, we report the synthesis of ultra-long MoS2 nano-channels with several micrometer length and 2-30 nanometer width within the MoSe2 monolayers, based on intrinsic grain boundaries (GBs). First-principles calculations disclose that the strain fields near the GBs not only lead to the preferred substitution of selenium by sulfur but also drive coherent extension of the MoS2 channel from the GBs. Such a strain-driven synthesis mechanism is further shown applicable to other topological defects. We also demonstrate that the spontaneous strain of MoS2 nano-channels can further improve the hydrogen production activity of GBs, paving the way for designing GB based high-efficient TMDs in the catalytic application.

Air-Stable Monolayer Cu2 Se Exhibits a Purely Thermal Structural Phase Transition.

Materials possessing structural phase transformations exhibit a rich set of physical and chemical properties that can be used for a variety of applications. In 2D materials, structural transformations have so far been induced by strain, lasers, electron injection, electron/ion beams, thermal loss of stoichiometry, and chemical treatments or by a combination of such approaches and annealing. However, stoichiometry-preserving, purely thermal, reversible phase transitions, which are fundamental in physics and can be easily induced, have not been observed. Here, the fabrication of monolayer Cu2 Se, a new 2D material is reported, demonstrating the existence of a purely thermal structural phase transition. Scanning tunneling microscopy, scanning transmission electron microscopy, and density functional theory (DFT) identify two structural phases at 78 and 300 K. DFT calculations trace the phase-transition mechanism via the existence/absence of imaginary (unstable) phonon modes at low and high temperatures. In situ, variable-temperature low-energy electron diffraction patterns demonstrate that the phase transition occurs across the whole sample at ≈147 K. Angle-resolved photoemission spectra and DFT calculations show that a degeneracy at the Γ point of the energy bands of the high-temperature phase is lifted in the low-temperature phase. This work opens up possibilities for studying such phase transitions in 2D materials.

Plasmon-induced hot electron transfer in Au-ZnO heterogeneous nanorods for enhanced SERS.

Colloid-synthesized matchstick-shaped Au-ZnO heterogeneous nanorods are found to have the Zn ion terminated plane in the ZnO-Au interface without the formation of Au-O bonds based on the atomic-resolution observation of their interfacial structure and electronic states, which is greatly different from the other reported results. The Au-ZnO heterogeneous nanorods with a good expitaxial interface have shown a stronger surface-enhanced Raman scattering (SERS) signal of the dopamine molecules than Au nanoscale seeds alone, which is attributed to the enhanced charge transfer (CT) effect of ZnO which is greatly improved by the plasmon-induced hot electron from Au nanostructures. The enhanced CT effect has also been proved by a higher photocatalysis efficiency. Furthermore, the plasmon-induced hot electron transfer mechanism in Au-ZnO heterogeneous nanorods has been confirmed by a slow rise time of electrons in the transient absorption measurements. These findings suggest the dependency of the plasmon-induced hot electron transfer mechanism on the different mixing of the metal and semiconductor band levels.