2,708 results match your criteria: "* National Institute for Materials Science NIMS[Affiliation]"

Reduced thermal conductivity and enhanced TE performance in CrSbvia Fe-Bi co-substitution.

Nanotechnology

August 2024

Research Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Namiki 1-1, Tsukuba 305-0044, Japan.

The efficiency of thermoelectric (TE) technology relies on the performance of TE materials. Substitution with heavy elements is an effective strategy in TE for enhancing phonon scattering without much affecting electrical transport properties. However, selecting suitable dopants to achieve a high TE figure-of-merit () poses a significant challenge.

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Four new alkaloids Chaeronepaline-A (1), Chaeronepaline-B (2), Chaeronepaline-C (3), and Chaeronepaline-D (4) were isolated from Corydalis chaerophylla D.C. collected from Nepal and their structures were elucidated by spectroscopic data, 1D, 2D NMR and mass spectrometry.

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There is a synergy between coordination chemistry and supramolecular chemistry that has led to the development of innovative hierarchical composites with diverse functionalities. Here, we present a novel approach for the synthesis and characterization of a metal-organic framework on fullerene (MOFOF) composites, achieved through the integration of coordination chemistry and supramolecular chemistry principles. The hierarchical nature of the MOFOF harnesses the inherent properties of metal-organic frameworks and fullerenes.

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Tetraborylation of -Benzynes Generated by the Masamune-Bergman Cyclization through Reaction Design Based on the Reaction Path Network.

JACS Au

July 2024

ERATO Maeda Artificial Intelligence in Chemical Reaction Design and Discovery Project, JST, Sapporo 060-0810, Hokkaido, Japan.

Article Synopsis
  • The study explored a new tetraborylation reaction involving -benzyne derived from 1,2-diethynylbenzene derivatives using bis(pinacolato)diborane(4).
  • Utilizing the artificial-force-induced reaction (AFIR) method, researchers identified both desired and undesired reaction pathways to refine the reactant's chemical structure.
  • Ultimately, the optimal reactant was found to be a 1,2-diethynylbenzene derivative with a butylene linker, leading to successful tetraborylated products with yields up to 58%.
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Mechanism of charge accumulation in potassium poly(heptazine imide).

Phys Chem Chem Phys

July 2024

Department of Physics and Astronomy, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan.

Dark photocatalysis is the ability of a photocatalyst to accumulate photocarriers during light irradiation and consume them for redox reactions under dark conditions. This phenomenon of photocatalysts storing photocarriers is known as charge accumulation. Dark photocatalysts can mitigate fluctuations in photocatalytic reaction efficiency in response to fluctuating solar irradiation.

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High Entropy Alloys (HEAs) are a versatile material with unique properties, tailored for various applications. They enable pH-sensitive electrocatalytic transformations like hydrogen evolution reaction (HER) and hydrogen oxidation reactions (HOR) in alkaline media. Mesoporous nanostructures with high surface area are preferred for these electrochemical reactions, but designing mesoporous HEA sis challenging.

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Quadrupling the depairing current density in the iron-based superconductor SmFeAsOH.

Nat Mater

October 2024

MDX Research Center for Element Strategy, International Research Frontiers Initiative, Tokyo Institute of Technology, Yokohama, Japan.

Article Synopsis
  • Iron-based 1111-type superconductors are known for their high critical temperatures and current densities, but traditional methods to increase current density (J) are limited.
  • Researchers improved J in SmFeAsOH films by increasing carrier density via high electron doping, which significantly reduced penetration depth and coherence length.
  • This innovative approach led to a remarkable increase in J to 415 MA/cm, comparable to cuprate superconductors, and demonstrated successful application across other iron-based superconductors as well.
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Lithium (Li) metal negative electrodes have attracted wide attention for high-energy-density batteries. However, their low coulombic efficiency (CE) due to parasitic electrolyte reduction has been an alarming concern. Concentrated electrolytes are one of the promising concepts that can stabilize the Li metal/electrolyte interface, thus increasing the CE; however, its mechanism has remained controversial.

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Compositional analysis (CA)-identification and quantification of the system constituents-is the most fundamental and decisive approach for investigating the system of interest. Pyrolysis mass spectrometry (MS) with a high resolution of over 10 000 is very effective for chemical identification and is directly applicable to polymer materials regardless of their solubilities. However, it is less helpful for quantification, especially when the references, , pure constituents, are unknown, non-isolable and thus cannot be prepared.

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Liquid-Liquid and Liquid-Solid Interfacial Nanoarchitectonics.

Molecules

July 2024

Research Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Ibaraki 305-0044, Japan.

Nanoscale science is becoming increasingly important and prominent, and further development will necessitate integration with other material chemistries. In other words, it involves the construction of a methodology to build up materials based on nanoscale knowledge. This is also the beginning of the concept of post-nanotechnology.

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Amplifying Photochromic Response in Tungsten Oxide Films with Titanium Oxide and Polyvinylpyrrolidone.

Nanomaterials (Basel)

June 2024

Lab of Organic Photo-Functional Materials, Department of Materials Science and Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea.

Tungsten oxide (WO) is known for its photochromic properties, making it useful for smart windows, displays, and sensors. However, its small bandgap leads to rapid recombination of electron-hole pairs, resulting in poor photochromic performance. This study aims to enhance the photochromic properties of WO by synthesizing hexagonal tungsten oxide via hydrothermal synthesis, which increases surface area and internal hydrates.

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Carbon electrodes typically display sluggish electron transfer kinetics due to the adsorption of adventitious molecules that effectively insulate the surface. Here, we describe a method for rendering graphitic carbon electrodes permanently hydrophilic by functionalization with 4-(diazonium)benzenesulfonic acid. In aqueous electrolytes, these hydrophilic carbon electrodes exhibit metal-like specific capacitance (∼40 μF/cm) as measured by cyclic voltammetry, suggesting a change in the double-layer structure at the carbon surface.

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Origin of O Generation in Sulfide-Based All-Solid-State Batteries and its Impact on High Energy Density.

Adv Sci (Weinh)

September 2024

Department of Material Design Innovation Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8603, Japan.

Article Synopsis
  • The study focuses on the issue of degradation in the amorphous-LiNbO coating of sulfide-based all-solid-state batteries (SBs) during high-voltage charging, which negatively impacts battery performance.
  • Researchers found that oxygen (O) is generated from the Li extraction in the coating layer, resulting in an oxidative solid electrolyte that further deteriorates battery efficiency.
  • By substituting elements in the coating (specifically using amorphous-LiNbP O), oxygen release is minimized, leading to more stable charge-discharge reactions and improved energy density in SBs.
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Time-resolved X-ray magnetic circular dichroism under the effects of ferromagnetic resonance (FMR), known as X-ray ferromagnetic resonance (XFMR) measurements, enables direct detection of precession dynamics of magnetic moment. Here we demonstrated XFMR measurements and Bayesian analyses as a quantitative probe for the precession of spin and orbital magnetic moments under the FMR effect. Magnetization precessions in two different Pt/Ni-Fe thin film samples were directly detected.

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Metal-support interaction engineering is considered an efficient strategy for optimizing the catalytic activity. Nevertheless, the fine regulation of metal-support interactions as well as understanding the corresponding catalytic mechanisms (particularly those of non-carbon support-based counterparts) remains challenging. Herein, a controllable adsorption-impregnation strategy was proposed for the preparation of a porous nonlayered 2D NiO nanoflake support anchored with different forms of Pt nanoarchitectures, single atoms, clusters and nanoparticles.

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Interface-Interactive Nanoarchitectonics: Solid and/or Liquid.

Chemphyschem

October 2024

Research Center for Materials Nanoarchitectonics, National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, 305-0044, Japan.

The methodology of nanoarchitectonics is to construct functional materials using nanounits such as atoms, molecules, and nanoobjects, just like architecting buildings. Nanoarchitectonics pursues the ultimate concept of materials science through the integration of related fields. In this review paper, under the title of interface-interactive nanoarchitectonics, several examples of structure fabrication and function development at interfaces will be discussed, highlighting the importance of architecting materials with nanoscale considerations.

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The introduction of phosphorous (P), and oxygen (O) heteroatoms in the natural honeydew chemical structure is one of the most effective, and practical approaches to synthesizing activated carbon for possible high-performance energy storage applications. The performance metrics of supercapacitors depend on surface functional groups and high-surface-area electrodes that can play a dominant role in areas that require high-power applications. Here, we report a phosphorous and oxygen co-doped honeydew peel-derived activated carbon (HDP-AC) electrode with low surface area for supercapacitor via HPO activation.

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Bio-gel nanoarchitectonics in tissue engineering.

Nanoscale

July 2024

Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwa-no-ha, Kashiwa 277-8561, Japan.

Given the creation of materials based on nanoscale science, nanotechnology must be combined with other disciplines. This role is played by the new concept of nanoarchitectonics, the process of constructing functional materials from nanocomponents. Nanoarchitectonics may be highly compatible with applications in biological systems.

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Molecular hydrogen (H) ortho-para conversion (O/P conversion) proceeds slowly at low temperatures accompanying a heat release. Thus, catalysts for accelerating this conversion rate are highly demanded in terms of the storage and utilization of liquid H. The catalysts for this purpose are experimentally screened by examining a broad range of materials covering magnetic, non-magnetic, metallic, and nonmetallic oxides.

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Data-Driven Cycle Life Prediction of Lithium Metal-Based Rechargeable Battery Based on Discharge/Charge Capacity and Relaxation Features.

Adv Sci (Weinh)

September 2024

Department of Nanoscience and Nanoengineering, Faculty of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, 169-8555, Japan.

Achieving precise estimates of battery cycle life is a formidable challenge due to the nonlinear nature of battery degradation. This study explores an approach using machine learning (ML) methods to predict the cycle life of lithium-metal-based rechargeable batteries with high mass loading LiNiMnCoO electrode, which exhibits more complicated and electrochemical profile during battery operating conditions than typically studied LiFePO₄/graphite based rechargeable batteries. Extracting diverse features from discharge, charge, and relaxation processes, the intricacies of cell behavior without relying on specific degradation mechanisms are navigated.

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Studying multiple properties of a material concurrently is essential for obtaining a comprehensive understanding of its behavior and performance. However, this approach presents certain challenges. For instance, simultaneous examination of various properties often necessitates extensive experimental resources, thereby increasing the overall cost and time required for research.

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Anchoring Cs Ions on Carbon Vacancies for Selective CO Electroreduction to CO at High Current Densities in Membrane Electrode Assembly Electrolyzers.

Angew Chem Int Ed Engl

October 2024

Advanced Catalytic Materials Research Center, School of Materials Science and Engineering, Tianjin University, Tianjin, 300072, China.

Electrolyte cations have been demonstrated to effectively enhance the rate and selectivity of the electrochemical CO reduction reaction (CORR), yet their implementation in electrolyte-free membrane electrode assembly (MEA) electrolyzer presents significant challenges. Herein, an anchored cation strategy that immobilizes Cs on carbon vacancies was designed and innovatively implemented in MEA electrolyzer, enabling highly efficient CO electroreduction over commercial silver catalyst. Our approach achieves a CO partial current density of approximately 500 mA cm in the MEA electrolyzer, three-fold enhancement compared to pure Ag.

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The size and site dependences of atomic and electronic structures in isolated and supported gold nanoparticles have been investigated using large-scale density functional theory (DFT) calculations using multi-site support functions. The effects of the substrate on nanoparticles with diameters of 2 nm and several different shapes have been examined. First, isolated gold nanoparticles with diameters of 0.

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Design of Apoptotic Cell-Inspired Particles as a Blood Coagulation Test.

Biomimetics (Basel)

June 2024

Research Center for Macromolecules and Biomaterials, National Institute for Materials Science (NIMS), Tsukuba 305-0044, Ibaraki, Japan.

The blood coagulation test is an indispensable test for monitoring the blood coagulation and fibrinolysis functions. Currently, activated partial thromboplastin time (APTT) is the most widely used approach to coagulation testing. However, APTT reagents need to be optimized due to the fact that they are unstable, highly variable, and cannot be easily controlled.

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In order to obtain thermally stable thin-film materials with high dielectric constant, ABO thin films (SrTaO, SrNbO, LaZrO, and LaTiO) containing Sr or La and their solid solutions were grown on Pt/Ti/SiO/Si substrates by RF sputtering and their crystal structures and dielectric properties were investigated. The SrTaO and LaTiO films exhibit highly oriented crystal structures. By contrast, the SrNbO and LaZrO films exhibit polycrystalline structures.

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