A5066077114- earthquake and tectonic studies
- Advanced Condensed Matter Physics
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Magnetic and transport properties of perovskites and related materials
- High-pressure geophysics and materials
- Geological and Geochemical Analysis
- Inorganic Chemistry and Materials
- Ammonia Synthesis and Nitrogen Reduction
- Hydrogen Storage and Materials
- Iron-based superconductors research
- Catalytic Processes in Materials Science
- Astro and Planetary Science
- Advancements in Battery Materials
- Ferroelectric and Piezoelectric Materials
- Multiferroics and related materials
- Layered Double Hydroxides Synthesis and Applications
- Physics of Superconductivity and Magnetism
- MXene and MAX Phase Materials
- Electronic and Structural Properties of Oxides
- Planetary Science and Exploration
- Perovskite Materials and Applications
- Inorganic Fluorides and Related Compounds
- Rare-earth and actinide compounds
- Extraction and Separation Processes
King Abdullah University of Science and Technology
2022-2025
Kyoto University
2012-2021
University of Tsukuba
1991-2018
Japan Science and Technology Agency
2010-2018
University of California, Berkeley
2009-2010
Lawrence Berkeley National Laboratory
2010
Kyoto University Research Reactor Institute
2010
Pennsylvania State University
2006-2009
Arizona State University
2009
Intel (United States)
2008
Iridium oxide nanoparticles stabilized by a heteroleptic ruthenium tris(bipyridyl) dye were used as sensitizers in photoelectrochemical cells consisting of nanocrystalline anatase anode and Pt cathode. The coordinated the IrO(2) x nH(2)O through malonate group porous TiO(2) electrode phosphonate groups. Under visible illumination (lambda > 410 nm) pH 5.75 aqueous buffer, oxygen was generated at potentials positive -325 mV vs Ag/AgCl hydrogen internal quantum yield for photocurrent generation...
The new microporous metal−organic framework Cu[Ni(pdt)2] (pdt2− = pyrazine-2,3-dithiolate) is demonstrated to have an optical bandgap, p-type semiconductivity, and redox activity. compound can be doped by using I2 as oxidant, leading increase in conductivity 4 orders of magnitude with retention porosity.
Abstract Rechargeable magnesium batteries are poised to be viable candidates for large-scale energy storage devices in smart grid communities and electric vehicles. However, the density of previously proposed rechargeable is low, limited mainly by cathode materials. Here, we present new design approaches order realize a high-energy-density battery system. Ion-exchanged MgFeSiO 4 demonstrates high reversible capacity exceeding 300 mAh·g −1 at voltage approximately 2.4 V vs. Mg. Further,...
The present report demonstrates a new technique for doping heteroatoms (nitrogen, phosphorus, and sulfur) into carbon materials via versatile post-treatment. heat-treatment of with reagent, which is stable at ambient temperatures evolves reactive gases on heating, in vacuum-closed tube allows the introduction various heteroatom-containing functional groups matrix. In addition, sequential reactions give rise to dual- triple-heteroatom-doped carbons. pore properties precursor are preserved...
The problem of activating N2 and its subsequent hydrogenation to form NH3 has been approached from many directions. One these approaches involves the use transition metal hydride complexes. Recently, complexes Ti Ta have shown activate N2, but without catalytic formation NH3. Here, we show that at elevated temperatures (400 °C, 5 MPa), solid-state hydride-containing compounds (TiH2 BaTiO2.5H0.5) a nitride-hydride surface similar those observed with titanium clusters, continuously (∼7 days)...
The sluggish anodic oxygen evolution reaction (OER) in proton exchange membrane (PEM) electrolysis necessitates applied bias to facilitate electron transfer as well bond cleavage and formation. Traditional electrocatalysis focuses on analyzing the effects of transfer, while role charge accumulation induced by overpotential has not been thoroughly investigated. To explore influence mechanism bias-driven accumulation, capacitive Mn is incorporated into IrO
Serpentinized peridotite is detected seismologically by mapping Poisson's ratio beneath the Kanto district, central Japan, because serpentinite has a higher than other rocks in crust and upper mantle. We determine three‐dimensional P S wave velocity models using travel time tomography then construct map of Poisson';s ratio. The show low anomalies near boundary slab depth range from 20 to 70 km. In region, there an area with greater 0.3 at depths 20–45 km, which we attribute serpentinized...
Abstract Ammonia is an attractive energy carrier for the hydrogen economy, given its high density and ease of liquefaction. A titanate oxyhydride has recently been demonstrated that can catalyze ammonia synthesis without Ru or Fe metal, despite titanium being regarded as inert element. Here, activity examined when Ru, Fe, Co particles are supported onto BaTiO 2.5 H 0.5 . The support significantly higher than 3 For example, increases by a factor 70–400, making them more active Ru/MgO, one...
The seismicity in the subducting Philippine Sea slab (PHS) beneath southwest Japan shows a variety of modes occurrence. We try to explain this on basis dehydration embrittlement oceanic crust and/or mantle. PHS along Nankai Trough commonly single narrow seismic zone shallower than 60 km, which may reflect hydrated only, implying lack Kanto, however, double (Hori, 1997) mantle part. Here serpentinized wedge Izu-Bonin fore-arc is subducting, and can be explained by its dehydration. Beneath Kii...
Monolithic conductive titanium oxides Ti(n)O(2n-1) (n = 2, 3, 4, 6) with well-defined macropores have been successfully prepared as a single phase, via reduction of macroporous TiO(2) precursor monolith using zirconium getter. Despite substantial removal oxide ions, all the reduced monoliths retain macropore properties precursor, i.e., uniform pore size distribution and volume. Furthermore, compared to commercial porous Ebonex (shaped Ti(n)O(2n-1)), bulk densities (1.8 g cm(-3)) are half,...
Well-dispersed Rh(OH)3 nanoparticles were deposited in the interlayer galleries of a Dion−Jacobson type layered perovskite (ACa2Nb3O10: A = H or K). X-ray photoelectron spectra and ζ potential measurements suggest covalent bonding (Rh−O−Nb) between niobate sheets. After calcination Rh(OH)3/KCa2Nb3O10 at 350 °C air, transformed to Rh2O3 showed higher photocatalytic activity for hydrogen evolution using methanol as sacrificial electron donor.
The nanoscroll-to-nanotube thermal transformation was studied for H4Nb6O17·4.4H2O scrolls, prepared by exfoliation of K4Nb6O17. Thermal dehydration the scrolls produces Nb2O5 nanotubes at 400−450 °C. nontopochemical results in polycrystalline nanotubes; however, significant texturing with respect to tube axis is observed. Substituting Ta Nb precursor compound led a lower yield most likely because there less built-in lattice strain drive scrolling unilamellar colloidal sheets.
Cation-exchangeable d(0) layered perovskites are amenable to intercalation, exfoliation, and a variety of topochemical reactions, but they lack the interesting electronic magnetic functionalities mixed-valent perovskites. Conversely, electronically magnetically scope in terms interlayer chemistry. To bridge this gap, insulating, cation-exchangeable RbLaNb(2)O(7), KCa(2)Nb(3)O(10), NaYTiO(4) were reacted with poly(tetrafluoroethylene) under inert atmosphere conditions yield layer which some...
Epitaxial thin films of titanium perovskite oxyhydride ATiO(3-x)H(x) (A = Ba, Sr, Ca) were prepared by CaH(2) reduction epitaxial ATiO(3) deposited on a (LaAlO(3))(0.3)(SrAl(0.5)Ta(0.5)O(3))(0.7) substrate. Secondary ion mass spectroscopy detected substantial amount and uniform distribution hydride within the film. SrTiO(3)/LSAT film hydridized at 530 °C for 1 day had concentration 4.0 × 10(21) atoms/cm(3) (i.e., SrTiO(2.75)H(0.25)). The electric resistivity all exhibited metallic (positive)...
We prepared a new two-dimensional oxyantimonide, BaTi 2 Sb O, which shows superconducting transition at 1.2 K, representing the first superconductivity in system with Ti 3+ ( d 1 ) square lattice. The TiO 4 mixed anionic coordination stabilizes unique half-filled x y orbital configuration O plane, is analogous to Cu 2+ 9 high- T c superconductors. A charge density wave (CDW)- or spin (SDW)-like anomaly appears 50 significantly reduced compared 200 K for isostructural and non-superconducting As O.
We report a novel oxyhydride SrCrO2H directly synthesized by high-pressure high-temperature method. Powder neutron and synchrotron X-ray diffraction revealed that this compound adopts the ideal cubic perovskite structure (Pm3̄m) with O(2-)/H(-) disorder. Surprisingly, despite non-bonding nature between Cr 3d t(2g) orbitals H 1s orbital, it exhibits G-type spin ordering at T(N)≈380 K, which is higher than of RCrO3 (R=rare earth) any chromium oxides. The enhanced T(N) in four Cr-O-Cr bonds...
The oxyhydride solid solutions (Ca,Sr)TiO(3-x)H(x) and (Sr,Ba)TiO(3-x)H(x) have been prepared by reducing the corresponding ATiO(3) oxides with calcium hydride. Under reaction conditions examined, a hydride content of x = 0.1-0.3 was obtained for all compositions. Compared to our previous result BaTiO(3-x)H(x), larger particle size in this study (20-30 μm vs 170 nm) resulted somewhat lower amount despite prolonged times. We examined changes cell volume, octahedral tilt angle, site occupancy...
Novel MgFePO<sub>4</sub>F exhibits a promising feasibility as cathode material for Mg batteries in spite of its cationic-disordered crystal structure.
While cation order–disorder transitions have been achieved in a wide range of materials and provide crucial effects various physical chemical properties, anion analogues are scarce. Here we expanded the number known lanthanide oxyhydrides, LnHO (Ln = La, Ce, Pr, Nd), to include Ln Sm, Gd, Tb, Dy, Ho, Er, which has allowed observation an transition from anion-ordered fluorite structure (P4/nmm) for larger Ln3+ ions (La–Nd) disordered arrangement (Fm3̅m) smaller (Sm–Er). Structural analysis...
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....
The relationship between crystal quality and the properties of indium phosphide nanowires grown on silicon (111) has been studied by transmission electron microscopy, photoluminescence spectroscopy, photoelectrochemistry. Wires with no defects {111} twin boundaries parallel perpendicular to growth direction were obtained metalorganic vapor-phase epitaxy using liquid catalyst. Room temperature from defect-free is ∼7 times more intense than that wires boundaries. An open-circuit photovoltage...