Revealing Robust Room Temperature Ferromagnetism in Gd-Doped Few-Layered MoS Thin Films.

2D MoS holds great promise for spintronics, yet is limited by intrinsic diamagnetism. This study demonstrates inducing ferromagnetic behavior in MoS films doped with 0.47% Gd, achieving an ultrahigh saturation magnetization of 454 emu/cm in a few-layered film over 11-times higher than bulk films (40 nm).

Ag Nanocrystals Intercalated Muscovite Mesocrystal for Large-Scale 3D SERS.

Plasmonic nanocrystals represent one of the most fascinating emerging research fields and hold great promise for a wide range of new applications, including surface-enhanced Raman spectroscopy (SERS) and plasmon-related devices. Here, we present a mesocrystal consisting of 3D Ag nanocrystals (NCs) with the same orientation intercalated in a 2D muscovite crystal via a two-step hydrothermal process for a novel SERS platform. The fabricated Ag NCs/mica mesocrystal possesses high crystallinity, uniform size, and extensive distribution to benefit the SERS-active plasmon area and strong plasmon resonance in the visible spectral range.

Lattice Oxygen Mechanism Induced on Nickel Sites by Cl Adsorption for Efficient Seawater Oxidation Reaction.

Efficient seawater oxidation reaction is crucial for advancing hydrogen fuel production. Developing highly efficient oxygen evolution reaction (OER) catalysts that follow the lattice oxygen mechanism (LOM) can effectively mitigate undesirable chloride oxidation side reactions in seawater electrolysis and reduce energy consumption. Herein, we propose a Cl-mediation strategy that is able to shift the OER mechanism from the adsorbate evolution mechanism (AEM) to LOM on nickel sites.

Resolving Dynamic Behavior of Electrocatalysts via Advances of Operando X-Ray Absorption Spectroscopies: Potential Artifacts and Practical Guidelines.

Although numerous techniques are developed to enable real-time understanding of dynamic interactions at the solid-liquid interface during electrochemical reactions, further progress in the development of these methods over the last several decades has faced challenges. With the rapid development of high-brilliance synchrotron sources, operando X-ray spectroscopies have become increasingly popular for revealing interfacial features and catalytic mechanisms in electrocatalysis. Nevertheless, the resulting spectra are highly sensitive to factors such as X-ray radiation, reaction environment, and acquisition procedures, all of which may potentially introduce artifacts that are often overlooked, leading to misinterpretations of electrocatalytic behaviors.

Planar chlorination engineering induced symmetry-broken single-atom site catalyst for enhanced CO electroreduction.

Breaking the geometric symmetry of traditional metal-N sites and further boosting catalytic activity are significant but challenging. Herein, planar chlorination engineering is proposed for successfully converting the traditional Zn-N site with low activity and selectivity for CO reduction reaction (CORR) into highly active Zn-N site with broken symmetry. The optimal catalyst Zn-SA/CNCl-1000 displays a highest faradaic efficiency for CO (FE) around 97 ± 3% and good stability during 50 h test at high current density of 200 mA/cm in zero-gap membrane electrode assembly (MEA) electrolyzer, with promising application in industrial catalysis.

Modulating Solid-Solution Solubility to Enhance Thermoelectric Performance and Maintain Structural Stability in Phase-Transition Silver Chalcogenides.

Silver chalcogenides exhibit exceptional transport properties but face structural instability at high temperatures, limiting their practical applications. Using AgTe as a model, it is confirm that silver whisker growth above the phase transition renders AgTe unsuitable for thermoelectric applications. Here, the whisker growth mechanism is investigated and propose an inhibition strategy, overcoming a major obstacle in using silver chalcogenides.

Superconductive MgB Intercalated Muscovite with Dynamically Tunable Stress.

In this study, we utilized a stress-sensitive superconductor MgB in combination with a flexible muscovite, a layered silicate, to demonstrate that materials in a reduced-dimension environment could be influenced by external strain. MgB nanocrystals were inserted into the muscovite interlayers using gas phase intercalation, creating a two-dimensional cavity-like structure. Several experiments confirmed that the cavity-induced static pressure from the intercalation effect and the external dynamic bending effect can affect the physical properties of MgB.

Homogeneous Catalytic Process of a Heterogeneous Ru Catalyst in Li-O via X-ray Nanodiffraction Observation.

In recent years, lithium oxygen batteries (Li-O) have received considerable research attention due to their extremely high energy density. However, the poor conductivity and ion conductivity of the discharge product lithium peroxide (LiO) result in a high charging overpotential, poor cycling stability, and low charging rate. Therefore, studying and improving catalysts is a top priority.

Solid Electrolyte Bimodal Grain Structures for Improved Cycling Performance.

The application of solid-state electrolytes in Li batteries is hampered by the occurrence of Li-dendrite-caused short circuits. To avoid cell failure, the electrolytes can only be stressed with rather low current densities, severely restricting their performance. As grain size and pore distributions significantly affect dendrite growth in ceramic electrolytes such as LiLaZrO and its variants; here, a "detour and buffer" strategy to bring the superiority of both coarse and fine grains into play, is proposed.

Self-carbon-thermal-reduction strategy for boosting the Fenton-like activity of single Fe-N sites by carbon-defect engineering.

Carbon-defect engineering in metal single-atom catalysts by simple and robust strategy, boosting their catalytic activity, and revealing the carbon defect-catalytic activity relationship are meaningful but challenging. Herein, we report a facile self-carbon-thermal-reduction strategy for carbon-defect engineering of single Fe-N sites in ZnO-Carbon nano-reactor, as efficient catalyst in Fenton-like reaction for degradation of phenol. The carbon vacancies are easily constructed adjacent to single Fe-N sites during synthesis, facilitating the formation of C-O bonding and lowering the energy barrier of rate-determining-step during degradation of phenol.

Self-Enhancement of Water Electrolysis by Electrolyte-Poled Ferroelectric Catalyst.

Efficient and durable electrocatalysts with superior activity are needed for the production of green hydrogen with a high yield and low energy consumption. Electrocatalysts based on transition metal oxides hold dominance due to their abundant natural resources, regulable physical properties, and good adaptation to a solution. In numerous oxide catalyst materials, ferroelectrics, possessing semiconducting characteristics and switchable spontaneous polarization, have been considered promising photoelectrodes for solar water splitting.

First principal observation documenting the three-dimensional uptake of cadmium and spatial distribution of cadmium hydroxyapatite mineral in bone char.

The 3-D matrix scale ion-exchange mechanism was explored for high-capacity cadmium (Cd) removal using bone chars (BC) chunks (1-2 mm) made at 500 °C (500BC) and 700 °C (700BC) in aqueous solutions. The Cd incorporation into the carbonated hydroxyapatite (CHAp) mineral of BC was examined using a set of synchrotron-based techniques. The Cd removal from solution and incorporation into mineral lattice were higher in 500BC than 700BC, and the diffusion depth was modulated by the initial Cd concentration and charring temperature.

Lightning-induced high temperature and pressure microstructures in surface and subsurface fulgurites.

Cloud-to-ground lightning causes both high-temperature and high-pressure metamorphism of rocks, forming rock fulgurite. We demonstrate that a range of microstructural features indicative of high temperatures and pressures can form in fulgurites at the surface and in fractures up to several meters below the surface. In comparison to a granite reference sample collected from a borehole at a depth of 138 m, microstructures in both the surface and fracture fulgurite are characterized by: (i) the presence of glass, (ii) a phase transformation in K-feldspar with the presence of exsolution lamellae of plagioclase, and (iii) high residual stresses up to 1.

Rapid Fabrication of High-Entropy Ceramic Nanomaterials for Catalytic Reactions.

Although high-entropy alloys have been intensively studied in the past decade, there are still many requirements for manufacturing processes and application directions to be proposed and developed, but most techniques are focused on high-entropy bulk materials and surface coatings. We fabricated high-entropy ceramic (HEC) nanomaterials using simple pulsed laser irradiation scanning on mixed salt solutions (PLMS method) under low-vacuum conditions. This method, allowing simple operation, rapid manufacturing, and low cost, is capable of using various metal salts as precursors and is also suitable for both flat and complicated 3D substrates.

Fabrication of Large-Scale High-Mobility Flexible Transparent Zinc Oxide Single Crystal Wafers.

Single crystal wafers, such as silicon, are the fundamental carriers of advanced electronic devices. However, these wafers exhibit rigidity without mechanical flexibility, limiting their applications in flexible electronics. Here, we propose a new approach to fabricate 1.

Twinning-mediated anomalous alignment of rutile films revealed by synchrotron X-ray nanodiffraction.

Nanotwin structures in materials engender fascinating exotic properties. However, twinning usually alter the crystal orientation, resulting in random orientation and limited performances. Here, we report a well-aligned rutile TiO nanotwin film with superior preferential orientation than its isostructural substrate.

Nanoporous Silver Telluride for Active Hydrogen Evolution.

Silver-based nanomaterials have been versatile building blocks of various photoassisted energy applications; however, they have demonstrated poor electrochemical catalytic performance and stability, in particular, in acidic environments. Here we report a stable and high-performance electrochemical catalyst of silver telluride (AgTe) for the hydrogen evolution reaction (HER), which was synthesized with a nanoporous structure by an electrochemical synthesis method. X-ray spectroscopy techniques on the nanometer scale and high-resolution transmission electron microscopy revealed an orthorhombic structure of nanoporous AgTe with precise lattice constants.

Nanoprobing of MoS by Synchrotron Radiation When van der Waals Epitaxy Is Locally Invalid.

In this work, we demonstrated nano-scaled Laue diffractions by a focused polychromatic synchrotron radiation beam to discover what happens in MoS when van der Waals epitaxy is locally invalid. A stronger exciton recombination with a local charge depletion in the density of 1 × 10 cm, extrapolated by Raman scattering and photoluminescence, occurs in grains, which exhibits a preferred orientation of 30° rotation with respect to the -plane of a sapphire substrate. Else, the charge doping and trion recombination dominate instead.

Electroreduction of CO to Formate on a Copper-Based Electrocatalyst at High Pressures with High Energy Conversion Efficiency.

Electrocatalytic CO reduction (CORR) to valuable fuels is a promising approach to mitigate energy and environmental problems, but controlling the reaction pathways and products remains challenging. Here a novel CuO nanoparticle film was synthesized by square-wave (SW) electrochemical redox cycling of high-purity Cu foils. The cathode afforded up to 98% Faradaic efficiency for electroreduction of CO to nearly pure formate under ≥45 atm CO in bicarbonate catholytes.

Element Effects on High-Entropy Alloy Vacancy and Heterogeneous Lattice Distortion Subjected to Quasi-equilibrium Heating.

We applied Simmons-Balluffi methods, positron measurements, and neutron diffraction to estimate the vacancy of CoCrFeNi and CoCrFeMnNi high-entropy alloys (HEAs) using Cu as a benchmark. The corresponding formation enthalpies and associated entropies of the HEAs and Cu were calculated. The vacancy-dependent effective free volumes in both CoCrFeNi and CoCrFeMnNi alloys are greater than those in Cu, implying the easier formation of vacancies by lattice structure relaxation of HEAs at elevated temperatures.

Depth-Profiling Electronic and Structural Properties of Cu(In,Ga)(S,Se)2 Thin-Film Solar Cell.

Utilizing a scanning photoelectron microscope (SPEM) and grazing-incidence X-ray powder diffraction (GIXRD), we studied the electronic band structure and the crystalline properties of the pentanary Cu(In,Ga)(S,Se)2 (CIGSSe) thin-film solar cell as a function of sample depth on measuring the thickness-gradient sample. A novel approach is proposed for studying the depth-dependent information on thin films, which can provide a gradient thickness and a wide cross-section of the sample by polishing process. The results exhibit that the CIGSSe absorber layer possesses four distinct stoichiometries.

Rutile-type (Ti,Sn)O₂ nanorods as efficient anode materials toward its lithium storage capabilities.

A series of rutile-type (Ti,Sn)O2 solid solutions with nanorod architecture were successfully synthesized in this study by varying their calcination temperatures of tin-modified titanium dioxide (Sn/TiO2) nanocomposites under a nitrogen atmosphere. During the delithiation process, the (Ti,Sn)O2 nanorods obtained at 500 °C delivered a specific capacity of about 300 mA h g(-1) and showed minimal capacity fading even at a high current density of 3 A g(-1).