69 results match your criteria: "National Institute for Materials Science (NIMS) 1-1 Namiki[Affiliation]"

Lateral nanoarchitectonics is a method of precisely designing functional materials from atoms, molecules, and nanomaterials (so-called nanounits) in two-dimensional (2D) space using knowledge of nanotechnology. Similar strategies can be seen in biological systems; in particular, biological membranes ingeniously arrange and organise functional units within a single layer of units to create powerful systems for photosynthesis or signal transduction and others. When our major lateral nanoarchitectural approaches such as layer-by-layer (LbL) assembly and Langmuir-Blodgett (LB) films are compared with biological membranes, one finds that lateral nanoarchitectonics has potential to become a powerful tool for designing advanced functional nanoscale systems; however, it is still rather not well-developed with a great deal of unexplored possibilities.

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Nanofibers containing activated carbon using poly(ethylene--vinyl alcohol) (EVOH) were prepared to remove indoxyl sulfate (IS) from the blood. IS is a urinary toxin that is highly toxic and triggers the progression of chronic kidney disease (CKD). Here, nanofibers containing activated carbon (AST-120), which has been used practically as an adsorbent for indole (a precursor of IS), were fabricated electrospinning for the adsorption and removal of IS from the blood.

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TiO remains one of the most popular materials used in catalysts, photovoltaics, coatings, and electronics due to its abundance, chemical stability, and excellent catalytic properties. The tailoring of the TiO structure into two-dimensional nanosheets prompted the successful isolation of graphene and MXenes. In this review, facet-controlled TiO and monolayer titanate are outlined, covering their synthesis route and formation mechanism.

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Lattice strain effects on the piezoelectric properties of crystalline ferroelectrics have been extensively studied for decades; however, the strain dependence of the piezoelectric properties at nano-level has yet to be investigated. Herein, a new overview of the super-strain of nanoporous polycrystalline ferroelectrics is reported for the first time using a nanoengineered barium calcium zirconium titanate composition (BaCa)(TiZr)O (BCZT). Atomic-level investigations show that the controlled pore wall thickness contributes to highly strained lattice structures that also retain the crystal size at the optimal value (<30 nm), which is the primary contributor to high piezoelectricity.

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The production of vanillin from biomass offers a sustainable route for synthesizing daily-use chemicals. However, achieving sunlight-driven vanillin synthesis through HO activation in an aqueous environment poses challenges due to the high barrier of HO dissociation. In this study, we have successfully developed an efficient approach for gram-scale vanillin synthesis in an aqueous reaction, employing Mn-defected γ-MnO as a photocatalyst at room temperature.

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A family of (alkylsilyl)pyrene-1-carboxamides exhibits similar mechanofluorochromic responses upon grinding. However, their spontaneous fluorescence recovery processes are distinct despite their similarity in chemical structures and crystal packings. Fluorescence spectroscopy, crystallography, and nanomechanical tests revealed that the chromic direction is dominated by the packing motif, while the fluorescence recovery is driven by the intermolecular interactions and the reversibility of deformation.

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Developing innovative catalysts for efficiently activating O into singlet oxygen (O) is a cutting-edge field with the potential to revolutionize green chemical synthesis. Despite its potential, practical implementation remains a significant challenge. In this study, we design a series of nitrogen (N)-doped manganese oxides (N-MnO, where represents the molar amount of the N precursor used) nanocatalysts using compartmentalized-microemulsion crystallization followed by post-calcination.

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Nicotine adenine dinucleotide derivatives NADH and NADPH are intimately involved in energy and electron transport within cells. The fluorescent ubiquinone-rhodol (Q-Rh) probe is used for NADPH activation monitoring. Q-Rh reacts with NADPH yielding its quenched hydroquinone-rhodol (HQ-Rh) form with concurrent NADPH activation ( NADP formation).

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Composite polymer electrolytes (CPEs) with high ionic conductivity and favorable electrolyte/electrode interfacial compatibility are promising alternatives to liquid electrolytes. However, severe parasitic reactions in the Li/electrolyte interface and the air-unstable inorganic fillers have hindered their industrial applications. Herein, surface-edge opposite charged Laponite (LAP) multilayer particles with high air stability were grafted with imidazole ionic liquid (IL-TFSI) to enhance the thermal, mechanical, and electrochemical performances of polyethylene oxide (PEO)-based CPEs.

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With the emergence of the energy crisis and the development of flexible electronics, there is an urgent need to develop new reliable energy supply devices with good flexibility, stable energy storage, and efficient energy transfer. Porous carbon materials have been proven to enhance the efficiency of ion transport, as the nanospaces within them serve as pathways for mass transport. However, they have been mainly investigated in the electrodes of supercapacitors and batteries.

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Article Synopsis
  • Solution-processed, cadmium-free quantum dot photodiodes show promise for optical sensing but struggled with slow response times due to low carrier mobility.
  • A novel InP-based photodiode with a multilayer architecture was developed, achieving fast response times (4 ms rise, 9 ms fall) in photovoltaic mode at room temperature.
  • The improved performance is attributed to effective carrier transportation in the quantum dots, efficient separation of charge carriers, and optimized thin film deposition, showcasing the potential of using coherent core/shell quantum dots for versatile and fast optical sensing applications.
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Data-Driven Design of Transparent Thermal Insulating Nanoscale Layered Oxides.

Micromachines (Basel)

January 2023

Research and Service Division of Materials Data and Integrated System (MaDIS), National Institute for Materials Science (NIMS) 1-1 Namiki, Tsukuba 305-0044, Ibaraki, Japan.

Predicting the interfacial thermal resistance (ITR) for various material systems is a time-consuming process. In this study, we applied our previously proposed ITR machine learning models to discover the material systems that satisfy both high transparency and low thermal conductivity. The selected material system of TiO2/SiO2 shows a high ITR of 26.

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The large-scale application of nanozymes remains a significant challenge owing to their unsatisfactory catalytic performances. Featuring a unique electronic structure and coordination environment, single-atom nanozymes provide great opportunities to vividly mimic the specific metal catalytic center of natural enzymes and achieve superior enzyme-like activity. In this study, the spin state engineering of Fe single-atom nanozymes (FeNC) is employed to enhance their peroxidase-like activity.

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Phosphor-converted white light emitting diodes (pc-LEDs) are efficient light sources for applications in lighting and electronic devices. Nitrides, with their wide-ranging applicability due to their intriguing structural diversity, and their auspicious chemical and physical properties, represent an essential component in industrial and materials applications. Here, we present the successful adsorption of Eu and Tb at the grain boundaries of bulk β-SiN and β-GeN by a successful combustion synthesis.

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In this study, we present microporous carbon (MPC), hollow microporous carbon (HMC) and hierarchically porous carbon (HPC) to demonstrate the importance of strategical designing of nanoarchitectures in achieving advanced catalyst (or electrode) materials, especially in the context of oxygen reduction reaction (ORR). Based on the electrochemical impedance spectroscopy and ORR studies, we identify a marked structural effect depending on the porosity. Specifically, mesopores are found to have the most profound influence by significantly improving electrochemical wettability and accessibility.

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Preparation of mesoporous nitrogen-doped titania comprising large crystallites with low thermal conductivity.

Nanoscale Adv

May 2022

Department of Applied Chemistry, School of Advanced Science and Engineering, Waseda University 3-4-1 Okubo, Shinjuku-ku Tokyo 169-8555 Japan.

Reducing the thermal conductivity () of mesoporous N-doped titania (TiO) is crucial for the development of TiO-based materials that exhibit excellent electronic, photochemical, and thermoelectric properties. Mesopores can contribute to the reduction of phonon scattering, and the scattering effect due to the randomness of crystal interfaces should be significantly reduced to clarify the role of mesopores in reducing thermal conductivity. Highly ordered mesoporous N-doped TiO comprising large crystallites was prepared with silica colloidal crystals as a template into which a Ti source was introduced, followed by calcination with urea.

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When the power conversion efficiency (PCE) of perovskite solar cells (PSCs) rapidly approaches that of commercial solar cells, the stability becomes the most important obstacle for the commercialization of PSCs. Aside from the widely studied slow PCE degradation, the PSCs also show a unique rapid PCE degradation. Although the degradation due to oxygen and humidity can be avoided by encapsulation, that due to bias voltage, light and heat could not be effective suppressed and will lead to considerable degradation.

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Solar-driven CO conversion into the industrial chemical CO the reverse water-gas reaction is an ideal technological approach to achieve the key step of carbon neutralization. The high reaction temperature is cost-free due to the photothermal conversion brought about by solar irradiation and is beneficial to the catalytic efficiency. However, the thermostability of adopted catalysts is a great challenge.

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Article Synopsis
  • * This method allows for the scalable production of centimetre-sized aerogels that are compressible and elastic, with customizable shapes and functions.
  • * The final product, carbon nanofiber aerogels (CNFAs), showcases unique properties such as low density, high mechanical strength, and exceptional adsorption capacity, paving the way for innovative multifunctional materials.
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Hole-Doping to a Cu(I)-Based Semiconductor with an Isovalent Cation: Utilizing a Complex Defect as a Shallow Acceptor.

J Am Chem Soc

September 2022

Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8503, Japan.

p-Type doping in Cu(I)-based semiconductors is pivotal for solar cell photoabsorbers and hole transport materials to improve the device performance. Impurity doping is a fundamental technology to overcome the intrinsic limits of hole concentration controlled by native defects. Here, we report that alkali metal impurities are prominent p-type dopants for the Cu(I)-based cation-deficient hole conductors.

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Porous architectures characterized by parallel channels arranged in honeycomb or rectangular patterns are identified in two polymorphic crystals of a zwitterionic 4-(aryliodonio)-benzenesulfonate. The channels are filled with disordered water molecules which can be reversibly removed on heating. Consistent with the remarkable strength and directionality of the halogen bonds (XBs) driving the crystal packing formation, the porous structure is stable and fully preserved on almost quantitative removal and readsorption of water.

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Flexible perovskite solar cells (PSCs) have attracted tremendous attention due to their potential application in portable and wearable electronics. However, the photoelectric conversion efficiency (PCE) of flexible PSCs is still far lower than that of usual rigid PSCs. Moreover, the mechanical stability of flexible PSCs cannot meet the needs of commercial applications because of the cracking of perovskite grains caused by bending stress.

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Spinel-type MgMnO, prepared by a propylene-oxide-driven sol-gel method, has a high surface area and structured bimodal macro- and mesopores, and exhibits good electrochemical properties as a cathode active material for rechargeable magnesium batteries. However, because of its hydrophilicity and significant water adsorption properties, macroscopic aggregates are formed in composite slurry-coated cathodes when 1-methyl-2-pyrrolidone (NMP) is used as a non-aqueous solvent. Functionalising the surface with phenylphosphonate groups was found to be an easy and effective technique to render the structured MgMnO hydrophobic and suppress aggregate formation in NMP-based slurries.

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In this review article, the recent examples of nanoarchitectonics on living cells are briefly explained. Not limited to conventional polymers, functional polymers, biomaterials, nanotubes, nanoparticles (conventional and magnetic ones), various inorganic substances, metal-organic frameworks (MOFs), and other advanced materials have been used as components for nanoarchitectonic decorations for living cells. Despite these artificial processes, the cells can remain active or remain in hibernation without being killed.

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Hexagonal BaTiOH Oxyhydride as a Water-Durable Catalyst Support for Chemoselective Hydrogenation.

J Am Chem Soc

April 2022

Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.

We present heavily H-doped BaTiOH ( ≈ 1) as an efficient and water-durable catalyst support for Pd nanoparticles applicable to liquid-phase hydrogenation reactions. The BaTiOH oxyhydride with a hexagonal crystal structure (6/) was synthesized by the direct reaction of BaH and TiO at 800 °C under a stream of hydrogen, and the estimated chemical composition was BaTiOH. Density functional theory calculations and magnetic measurements indicated that such heavy H doping results in a metallic nature with delocalized electrons and a low work function.

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