A5020554931- Advanced NMR Techniques and Applications
- Quantum Dots Synthesis And Properties
- Solid-state spectroscopy and crystallography
- Chalcogenide Semiconductor Thin Films
- Hydrogen Storage and Materials
- Advanced Condensed Matter Physics
- NMR spectroscopy and applications
- Metal-Organic Frameworks: Synthesis and Applications
- Advanced Battery Materials and Technologies
- Inorganic Fluorides and Related Compounds
- Nanocluster Synthesis and Applications
- Chemical Synthesis and Characterization
- Atomic and Subatomic Physics Research
- Covalent Organic Framework Applications
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Advancements in Solid Oxide Fuel Cells
- 2D Materials and Applications
- Membrane Separation and Gas Transport
- Electron Spin Resonance Studies
- Crystal Structures and Properties
- Advancements in Battery Materials
- Advanced Photocatalysis Techniques
- Microfluidic and Bio-sensing Technologies
- Gold and Silver Nanoparticles Synthesis and Applications
Kyoto University
2014-2024
Tohoku University
1990-2020
Graduate School USA
2019-2020
Japan Science and Technology Agency
2020
Arkray (Japan)
2010-2012
Solid state lithium conductors are attracting much attention for their potential applications to solid-state batteries and supercapacitors of high energy density overcome safety issues irreversible capacity loss the currently commercialized ones. Recently, we discovered a new class super ionic based on borohydride (LiBH(4)). LiBH(4) was found have conductivity as 10(-2) Scm(-1) accompanied by orthorhombic hexagonal phase transition above 115 degrees C. Polarization metal electrode shown be...
In synthesizing mixed anion oxides, direct syntheses have often been employed, usually involving high temperature and occasionally pressure. Compared with these methods, here we show how the use of a titanium perovskite oxyhydride (BaTiO2.5H0.5) as starting material enables new multistep low topochemical routes to access compounds. Similar labile ligands in inorganic complexes, lability H(-) provides necessary reactivity for syntheses, leading reactions products previously difficult obtain....
We report a scandium oxyhydride BaScO2H prepared by solid state reaction under high pressure. Rietveld refinements against powder synchrotron X-ray and neutron diffraction data revealed that adopts the ideal cubic perovskite structure (Pm3̅m), where oxide (O2-) hydride (H-) anions are disordered. 1H nuclear magnetic resonance (NMR) spectroscopy provides positive chemical shift of about +4.4 ppm, which can be understood distance to nearest (and possibly next nearest) cation from H nucleus. A...
The results of a single-crystal x-ray-diffraction study the evolution crystal structures $\mathrm{V}{\mathrm{I}}_{3}$ with temperature an emphasis on phase transitions are presented. Some related specific-heat and magnetization data included. existence room-temperature trigonal structure $R\overline{3}$ (148) has been confirmed. Upon cooling, undergoes structural transition to monoclinic at ${T}_{\mathrm{s}}\ensuremath{\sim}79\phantom{\rule{0.16em}{0ex}}\mathrm{K}$. ${T}_{\mathrm{s}}$ is...
Ligand molecules capping on clusters largely affect the formation and stabilization mechanism property of clusters. In semiconductor CdSe clusters, cysteine is used as one ligands allows ultrastable (CdSe)34 magic-sized Cysteine has sulfhydryl, amine, carboxylate groups, all which have coordination ability to surface, bonding states three functional groups ligand-cysteine core not been determined. this work, structure examined by performing Fourier transform infrared (FT-IR) spectroscopy,...
Ligand–surface interaction of semiconductor nanoparticles (NPs) controls their optoelectronic properties, and thus examination the is essential for nanoelectronic applications NPs. Herein, solid-state nuclear magnetic resonance (NMR) performed to unravel ligand–surface in cysteine-capped CdSe magic-sized clusters. 15N–113Cd through-bond J-filtered NMR directly shows presence nitrogen–cadmium chemical bond first time indicates that ∼43% amines form bond. through-space dipolar-correlated...
Experimental and computational studies of resonant Raman spectra truly monosized (CdSe)33 (CdSe)34 nanoclusters have been performed. First-principles calculations vibrations are performed to account for the peculiarity spectrum selection rules. The calculation method is based on analysis spatial distribution electron density in ground excited states corresponding displacement atoms after electronic transition. calculated vibrational CdSe a core-cage arrangement distinctively different from...
Two-dimensional (2D) covariance NMR spectroscopy, which has originally been established to extract homonuclear correlations (HOMCOR), is extended include heteronuclear (HETCOR). In a (13)C/(15)N 2D chemical shift correlation experiment, (13)C and (15)N signals of polycrystalline sample (13)C, (15)N-labeled amino acid are acquired simultaneously using dual-receiver system. The data sets rearranged for the processing, (13)C-(15)N obtained together with (13)C-(13)C (15)N-(15)N correlations....
The application of high-resolution NMR analysis for CO2 adsorbed in a MOF under high pressure is reported the first time. results showed that MOF-74 had an unusually slow mobility (τ ∼ 10-8 s). CO2-CO2 interactions suppressed pressure, which, turn, would have contributed to stability at adsorption sites.
Amorphous high-surface-area aluminum hydroxide-bicarbonates were synthesized starting from AlCl3, base, and bicarbonate in water. Composites with a chemical formulas of [Al13O4(μ-OH)24(H2O)6.5(OH)5.5](HCO3)1.5 (I-NaOH) [Al13O4(μ-OH)24(H2O)6(OH)6](HCO3) (I-NH3) obtained by the use NaOH/NaHCO3 NH3/NH4HCO3 as base/bicarbonate, respectively. The surface area composites was highly dependent on pH level synthetic solution, high areas (ca. 200 m2 g-1) around 7-8. Pore-size distributions determined...
Lithium overstoichiometric LixCoO2 (x > 1) with few phase transitions is promising as a positive electrode material for lithium ion batteries; however, the detailed local structures around excess Li ions remain unknown and need to be elucidated. It has been postulated that occupies Co site, resulting charge deficit compensated by oxygen vacancies valence of Co. Two spin states have invoked ion; one Co3+ taking an intermediate state (S = other low Co2+ 1/2). The paramagnetic shift caused...
Fluorine-doped VO2(M) nanoparticles have been successfully synthesized using the hydrothermal method at a supercritical temperature of 490 °C. The pristine has critical phase transformation 64 morphology and homogeneity monoclinic structure were adopted by fluorine-doped system. obtained particle size samples is smaller higher concentration anion doping. best reduction was achieved fluorine doping 0.13% up to 48 thin films showed pronounced thermochromic property therefore are suitable for...
Redox-active porous ionic crystals based on polyoxometalate (POM) were utilized to form and stabilize small mixed-valence luminescent silver clusters via cation-coupled electron-transfer (CCET) reactions. Reduction-induced ion-exchange between Cs+ Ag+via CCET took less than 1 min complete consisted of two steps: electron transfer from reduced POM Ag+ the subsequent formation a cluster, diffusion cluster exchange with Cs+. Notably, simple more 24 h. The compound containing showed high...
The success and continued expansion of research on metal-oxo clusters owe largely to their structural richness wide range functions. However, while most them known date are negatively charged polyoxometalates, there is only a handful cationic ones, much less functional ones. Here, we show an all-inorganic hydroxyiodide [H 10.7 Sb 32.1 O 44 ][H 2.1 I 8 6 ][Sb 0.76 ] 2 ·25H ( HSbOI ), forming face-centered cubic structure with 32 two types anionic in its interstitial spaces. Although it...
As an effort to develop a new, effective, nontoxic X-ray contrast agent, the concentrated colloids of silica-encapsulated gold nanoparticles (Au@SiO2 NPs) were fabricated and their colloidal stability, cytotoxicity, absorption investigated. The NPs manufactured by forming 4 nm-thick silica shell on surface each Au NP with 15 nm diameter, followed enrichment [Au] = 100 mM. They very stable in water: well separated other without agglomerates optical property was similar that before enrichment....