Hiromi Yamashita

Plasmonic materials have drawn emerging interest, especially in nontraditional semiconductor nanostructures with earth-abundant elements and low resistive loss. However, the actualization of highly efficient catalysis in plasmonic semiconductor nanostructures is still a challenge, owing to the presence of surface-capping agents in their synthetic procedures. To fulfill this, a facile non-aqueous procedure was employed to prepare well-defined molybdenum oxide nanosheets in the absence of surfacta

Design and engineering of metal–organic frameworks for the adsorption/degradation of inorganic toxic gases, organic vapors and particulate matter.

Superhydrophobic surfaces with photocatalytic self-cleaning properties are designed through coating a nanocomposite TiO(2) photocatalyst and hydrophobic polytetrafluoroethylene onto a structured substrate by applying a co-deposition technique. This coating realizes adequate photocatalytic activity for self-cleaning and inducing unique surface wettability changes. The nanocomposite can contain multiple functions, enabling energy-saving and maintenance-free characteristics.

Much effort has been devoted to photocatalytic production of hydrogen peroxide (H₂ O₂ ) as an alternative to fossil fuels. From an economic point of view, reductive synthesis of H₂ O₂ from O₂ coupled with the oxidative synthesis of value-added products is particularly interesting. We herein report application of MIL-125-NH₂ , a photoactive metal-organic framework (MOF), to a benzylalcohol/water two-phase system that realized photo

Silver nanoparticles (Ag NPs) of various colors were synthesized within the mesopore structure of SBA-15 by using microwave-assisted alcohol reduction. The charge density is partially localized on the surface of these Ag NPs owing to localized surface plasmon resonance. This charge localization results in them having enhanced catalytic activity under visible light irradiation compared to Ag NPs obtained by thermal processes.

Titanium oxide species anchored in the Y-zeolite cavities by an ion-exchange method exhibits a high and unique photocatalytic reactivity for the direct decomposition of NO into N2, O2, and N2O at 275 K with a high selectivity for the formation of N2. The in situ photoluminescence and XAFS (XANES and FT-EXAFS) investigations indicate that the titanium oxide species are highly dispersed in the zeolite cavities and exist in a tetrahedral coordination. The charge-transfer excited state of the titani

The characterization of the coordination geometry of copper ions included within zeolites has been carried out with a combination of in-situ XAFS, photoluminescence, and IR measurements in order to obtain a detailed description of the formation of isolated Cu+ monomers with planar 3-coordinate or linear 2-coordinate geometry in the zeolite channels by thermal treatment under vacuum. The Cu+ ions within the zeolites were found to exist as isolated Cu+ monomers and (Cu+−Cu+) dimers, their relative

Highly dispersed titanium oxide photocatalysts anchored onto transparent plates of porous silica glass were successfully prepared by metal ion implantation, and their photocatalytic reactivity for the liquid-phase photocatalytic degradation of an aqueous 2-propanol solution was compared with that in an aqueous TiO2 dispersion. The titanium ions implanted into the porous silica glass are found to be present on the surface layer as isolated tetrahedral titanium oxide moieties by diffuse reflectanc

The incorporation of Pt nanoparticles into a highly stable and porous amine-functionalized MIL-101(Cr) was performed for construction of a visible light driven H2 evolution system with high activity and strong stability.

A plasmonic hybrid having Pd nanoparticles on plasmonic MoO(3-x) is developed by a facile solution process, and its plasmonic resonance displays reversible tunability upon oxidation/reduction. Under visible-light irradiation, the Pd/MoO(3-x) hybrid exhibits plasmon-enhanced catalysis toward H2 evolution from ammonia borane hydrolysis and the Suzuki-Miyaura coupling reaction relative to dark conditions.

The metal ion-implantation of titanium oxide with metal ions (Cr + or V +) at high energy acceleration and the subsequent calcination of these metal ion-implanted TiO 2 in oxygen at around 725 K resulted in a large shift in the absorption spectra toward visible light regions. These catalysts exhibited effective and remarkable photocatalytic reactivity for various reactions such as the decomposition of NO into N2, 02 and N20 at 275 K not only under UV but also under visible light irradiation. XAF

Titanium−silicon (Ti/Si) binary oxides having different Ti contents were prepared by the sol−gel method and used as photocatalysts. The photocatalytic reactivity of these catalysts was investigated as a function of the Ti content for the liquid-phase oxidation of 1-octanol to 1-octanal, and it was found to be dramatically enhanced in regions of lower Ti content. In situ photoluminescence, UV−vis reflectance, FT-IR, ESR, XAFS, XRD, and XPS spectroscopic investigations of these Ti/Si binary oxides