A5066109673- Electronic and Structural Properties of Oxides
- Electron and X-Ray Spectroscopy Techniques
- Magnetic and transport properties of perovskites and related materials
- Advanced Electron Microscopy Techniques and Applications
- Advanced Condensed Matter Physics
- Semiconductor materials and devices
- Advancements in Battery Materials
- Advanced Photocatalysis Techniques
- Gold and Silver Nanoparticles Synthesis and Applications
- Force Microscopy Techniques and Applications
- Quantum Dots Synthesis And Properties
- Copper-based nanomaterials and applications
- Astro and Planetary Science
- Ferroelectric and Piezoelectric Materials
- Supercapacitor Materials and Fabrication
- Fusion materials and technologies
- Advanced Battery Materials and Technologies
- Nuclear Materials and Properties
- X-ray Diffraction in Crystallography
- ZnO doping and properties
- Multiferroics and related materials
- Magnetic properties of thin films
- Planetary Science and Exploration
- Chalcogenide Semiconductor Thin Films
- MXene and MAX Phase Materials
Kyoto Bunkyo University
2014-2024
Kyoto University
2015-2024
Kyoto University Institute for Chemical Research
2015-2024
Instituto de Investigaciones Químicas
2009-2021
Kyoto College of Medical Science
2019-2020
National Institute for Materials Science
2012-2015
Time resolved absorption spectroscopy has been used to study photoinduced electron injection and charge recombination in Zn-porphyrin sensitized nanostructured TiO2 electrodes. The transfer dynamics is correlated the performance of dye solar cells based on same We find that dye/semiconductor binding can be described with a heterogeneous geometry where Zn−porphyrin molecules are attached surface distribution tilt angles. angle determines porphyrin−semiconductor distance occurs through space,...
Localized surface plasmon resonance (LSPR)-induced hot-carrier transfer is a key mechanism for achieving artificial photosynthesis using the whole solar spectrum, even including infrared (IR) region. In contrast to explosive development of photocatalysts based on plasmon-induced hot electron transfer, hole system still quite immature regardless its importance, because has remained unclear. Herein, we elucidate LSPR-induced in CdS/CuS heterostructured nanocrystals (HNCs) time-resolved IR...
Creating semiconductor nanocages The surface area of nanomaterials can be increased by creating open cage structures. Now it seems that the shape nanocrystals used as a tool to manipulate crystal structure in nanocrystals. Wu et al. show how single copper oxide are converted through anion exchange reactions multiply twinned cages sulfide process changes lattice symmetries. These structures were then into cadmium cation exchange. Science , this issue p. 1306
Heterogeneous photocatalysis is vital in solving energy and environmental issues that this society confronted with. Although photocatalysts are often operated the presence of water, it has not been yet clarified how interaction with water itself affects charge dynamics photocatalysts. Using water-coverage-controlled steady transient infrared absorption spectroscopy large-model (∼800 atoms) ab initio calculations, we clarify enhances hole trapping at surface TiO2 nanospheres but well-faceted...
Abstract Transmission electron microscopy analyses of Hayabusa2 samples show that Ryugu organic matter exhibits a range morphologies, elemental compositions, and carbon functional chemistries consistent with those carbonaceous chondrites have experienced low‐temperature aqueous alteration. Both nanoglobules diffuse are abundant. Non‐globular particles also present, including some contain nanodiamond clusters. Diffuse is finely distributed in around phyllosilicates, forms coatings on other...
We investigated optical and transport properties of transparent conducting La-doped strontium stannate epitaxial thin films prepared by pulsed laser deposition. The are with no apparent absorptions in the wavelength range between 390 1600 nm. room-temperature electrical resistivity decreases increasing carrier concentration reaches values as low 1 mΩ cm. mobility shows maximum 40 cm2 (V s)−1 at a about 9 × 1019 cm−3. At that predominant mechanism changes from scattering lattice defects to...
Charge carrier trapping plays a vital role in heterogeneous photocatalytic water splitting because it strongly affects the dynamics of photogenerated charges and hence photoconversion efficiency. Although hole by at water/photocatalyst interface is first step oxygen evolution splitting, little has been known on how adsorbate itself involved dynamics. To clarify this point, we have performed infrared transient steady-state absorption spectroscopy anatase TiO2 nanoparticles as function number...
Perovskite solar cells (PSCs) are an innovative technology with great potential to offer cost-effective and high-performance devices for converting light into electricity that can be used both outdoor indoor applications. In this study, a novel hole-transporting layer (HTL) was created by mixing copper phthalocyanine (CuPc) molecules copper(I) thiocyanate (CuSCN) film applied carbon-based PSCs cesium/formamidinium (Cs0.17FA0.83Pb(I0.83Br0.17)3) as photoabsorber. At the optimum concentration,...
Abstract Two-dimensional freestanding membranes of materials, which can be transferred onto and make interfaces with any material, have attracted attention in the search for functional properties that utilized next-generation nanoscale devices. We fabricated stable 1-nm-thick hafnia exhibiting metastable rhombohedral structure out-of-plane ferroelectric polarizations as large 13 μC/cm 2 . also found phase transforms into another orthorhombic without ferroelectricity deteriorating thickness...
Photocatalytic conversion of solar energy to chemical is an efficient process in green chemistry because it facilitates room temperature transformations by generating electronically excited states photocatalysts. We report here on the robust synthesis, detailed structural characterization, and especially photocatalytic properties plasmonic Pd hexagonal nanoplates for reactions. The are twin crystals, composed top bottom faces enclosed {111} planes with stacking faults side surfaces bound...
Controlling the carrier dynamics in a semiconductor nanoparticulate photocatalyst is key to developing catalytic activity. Generally, type I band alignment unsuitable for photocatalysts because photoinduced carriers accumulate narrow bandgap semiconductor. To avoid termination of reactions and/or photocorrosion materials caused by accumulation, it common employ II photoenergy conversion systems instead I. However, CdS/ZnS core/mesoporous-shell heterostructures show superior photocatalytic...
Monodisperse and size-tunable PbS QDs were synthesized <italic>via</italic> the diffusion controlled reaction of turbid suspensions reactive <italic>N</italic>,<italic>N</italic>′-diphenylthiourea PbCl<sub>2</sub> precursors.
In artificial photosynthesis, the establishment of design guidelines for nanostructures to maximize photocatalytic performance remains a great challenge. contrast with intense research into band-offset tuning photocatalysts, relationship between and photoinduced carrier dynamics has still been insufficiently explored. We synthesized durian-shaped CdS@ZnSe core@mesporous-shell nanoparticles (d-CdS/ZnSe NPs) investigated in hydrogen evolution. The cocatalyst-free d-CdS/ZnSe NPs exhibited high...
Bimetallic selenide nanocrystals formed by cation exchange reaction work as a precursor of efficient water oxidation electrocatalyst.
Abstract Samples returned from the carbonaceous asteroid (162173) Ryugu by Hayabusa2 mission revealed that is composed of materials consistent with CI chondrites and some types space weathering. We report detailed mineralogy fine‐grained samples allocated to our “Sand” team additional weathering features found on grains. The dominant a mixture Mg‐rich saponite serpentine, magnetite, pyrrhotite, pentlandite, dolomite, Fe‐bearing magnesite. These grains have comparable chondrites, showing...
Bronze phase titanium dioxide (TiO2(B)) nanorods were successfully prepared via a hydrothermal method together with an ion exchange process and calcination by using anatase precursors in the alkali system. TiO2 promoted elongation of nanorod morphology. The different temperatures reaction times demonstrated that synthesis parameters had significant influence on formation physical morphologies during fabrication process. effects conditions tailoring crystal morphology discussed. growth...
The Hayabusa2 spacecraft delivered samples of the carbonaceous asteroid Ryugu to Earth. Some sample particles show evidence micrometeoroid impacts, which occurred on surface. Among those, A0067 and A0094 have flat surfaces a large number microcraters impact melt splashes are observed. Two one microcrater were analyzed unveil nature objects that impacted consist mainly Mg-Fe–rich glassy silicates Fe-Ni sulfides. trapped an consisting silicate, sulfides, minor silica-rich glass. These melts...
Oxygen K-edge and Fe L2,3-edge electron energy-loss near-edge structures (ELNES) were measured for FeO6 octahedra FeO4 tetrahedra in the brownmillerite Ca(Sr)FeO2.5 by focusing an probe at individual sites using scanning transmission microscopy combined with spectroscopy. The observed site-resolved oxygen K-ELNES showed different features reflecting local chemical bonding around tetrahedra. A pre-peak O spectra, which is attributed to a transition unoccupied 2p band hybridized Fe-3d band,...
The structural analysis of crystal defects in organic thin films provides fundamental insights into their electronic properties for applications such as field effect transistors. Observation has previously been performed at rather low resolution by conventional transmission electron microscopy based on phase-contrast imaging. Herein, we apply the first time annular dark-field imaging to direct observation grain boundaries copper hexachlorophthalocyanine atomic level using an...
Copper-deficient copper sulfide (Cu2-xS) nanoparticles (NPs) have been investigated as important hole-based plasmonic materials because of their size, morphology, and carrier density-dependent localized surface plasmon resonance (LSPR) properties. Morphology density are two parameters to determine LSPR Here, we demonstrate that the foreign metal ion, Sn(4+), directs growth djurleite Cu31S16 from nanodisk tetradecahedron along [100] direction. To control properties by tuning density, were...
Emerging technologies demand a new generation of lithium-ion batteries that are high in power density, fast-charging, safe to use, and have long cycle lives. This work reports charging rates specific capacities TiO2(B)/N-doped graphene (TNG) composites. The TNG composites were prepared by the hydrothermal method various reaction times (3, 6, 9, 12, 24 h), while N-doped was synthesized using modified Hummer's followed heat-treatment process. different morphologies TiO2 dispersed on sheet...