Shiro Kubuki

Shiro Kubuki
Tokyo Metropolitan Institute | TMU · Department of Chemistry

PhD

About

132
Publications
7,870
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877
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Additional affiliations
April 2010 - present
Tokyo Metropolitan University
Position
  • Professor (Associate)
January 1999 - March 2010
UBE National College of Technology
Position
  • Professor (Associate)

Publications

Publications (132)
Article
Full-text available
Dioximes as ligands are used as analytical reagents and serve as models for biological systems as well as catalysts in chemical processes. A number of novel mixed complexes of the type [Fe(DioxH) 2 (amine) 2 ] have been prepared and characterised by FTIR, ⁵⁷ Fe Mössbauer and mass spectroscopy by us. We have found strong Fe–N donor acceptor interact...
Article
Full-text available
Strontium ferromolybdate, Sr2FeMoO6, is an important member of the family of double perovskites with the possible technological applications in the field of spintronics and solid oxide fuel cells. Its preparation via a multi-step ceramic route or various wet chemistry-based routes is notoriously difficult. The present work demonstrates that Sr2FeMo...
Article
Full-text available
In this work, we report the effect of the addition of modifiers and network formers on the polaronic transport in iron phosphate glasses (IPG) in two systems of HfO2–B2O3–Fe2O3–P2O5, to which up to 8 mol% boron and hafnium are added. The addition of oxides significantly changes the Fe2+/Fetotal ratio, thus directly affecting the polaron number dens...
Article
Glass-ceramics xZrO2•10Fe2O3•(90-x)V2O5 with ‘x’ between 0 and 30 mol% and yZrO2・(20-y)CaO・10Fe2O3・70V2O5 glass with ‘y’ between 0 and 20 mol%, respectively abbreviated as xZFV and yZCFV, before and after heat treatment at 500 oC for 100 min, were evaluated as potential cathode-active materials for sodium-ion batteries (SIBs). Relationships between...
Article
A novel heterogeneous catalyst [email protected]2 was successfully synthesized via facile hydrothermal processes and identified as a superior peroxymonosulfate (PMS) activator for organic pollutants degradation under visible light irradiation. The MoS2 nanosheet is uniformly adhered to the surface of iron-based metal-organic framework Prussian blue...
Article
A highly efficient photo-Fenton catalyst iron silicate glass was successfully prepared by a simple sol-gel method. The characterization results (XRD, Mössbauer spectroscopy, TEM, and FT-IR) showed that fayalite, clinoferrosilite and hematite nanoparticles were precipitated in the glass system. The catalytic activity of the glass samples was evaluat...
Article
A relationship between local structure and electrical property of xNa2O·10P2O5·(90−x)V2O5 glass (x = 5, 25 and 45 mol%, abbreviated as xNPV) was investigated by means of ⁵⁷Fe-Mössbauer spectroscopy(FeMS), X-ray absorption fine structure (XAFS), X-ray diffractometry (XRD), impedance spectroscopy (IS), and cathode active performance test of Na-ion ba...
Article
Full-text available
This review paper summarizes early Mössbauer and DTA studies of different oxide glasses containing small amounts of iron (III) or tin (IV) as the probe. A lot of valuable information of the atomic level has been obtained about the role of nonbridging oxygen (NBO), network former (NWF), network modifier (NWM), local network structure, glass transiti...
Article
The relationship between local structure and visible-light-activated photocatalytic ability of glass–ceramics prepared from Municipal Solid Waste (MSW) was investigated. The samples were characterized by XRD, 57Fe Mössbauer spectroscopies, TEM and DRS. From the Mössbauer spectrum, it was found that iron ions are present in FeIII(tetrahedral) and Fe...
Article
Nanoparticles of ε-Fe2O3 in an amorphous silica matrix were prepared by the sol–gel method without using a precursor. X-ray diffraction patterns reflect a completely amorphous state for the samples even after heat-treated up to 600 °C, while at higher temperatures the formation of crystalline iron oxide phases was observed. Transmission electron mi...
Article
Municipal waste is an essential issue worldwide. The achievements in this field needs to be maximized to meet the increase in municipal waste generated every year. The challenge is to correlate municipal waste management systems to the high valued applications. The present work fills this gap by tracing the elemental analysis of municipal waste sla...
Article
The glass samples with the composition of 40Fe2O3-xAl2O3-(60−x)SiO2 were prepared by sol-gel method. The samples were characterized by XRD, 80 K ⁵⁷Fe Mössbauer spectroscopy, TEM, FTIR and impedance spectroscopy. In the glass samples with less than 10% alumina, fayalite and hematite were crystallized by addition of hercynite. Whereas nanoparticles o...
Article
Utilization of heterogenous catalysts to trigger peroxymonosulfate (PMS) activation is considered an efficient strategy for environmental decontamination. Herein, a tightly bonded flake-like 2D/2D BiOBr/MoS2 heterojunction was successfully designed through co-precipitation process. By virtue of matched energy levels and intimate interfacial couplin...
Article
Full-text available
Dilute Fe and Nb codoped SrTiO3-δ (STO) perovskites were prepared by a complex formation and thermal decomposition method. The structure, magnetization properties and chemical states of Fe and Nb codoped STO perovskites were characterized by XRD, VSM and Mössbauer spectrometry. Mössbauer spectra of ⁵⁷Fe and Nb codoped STO perovskites consist of par...
Article
Pure hematite nanorods and very long and thin cobalt-doped hematite nanorods (nanoneedles) were prepared by a combined precipitation and annealing method. The influence of the level of cobalt doping on different properties of hematite nanorods was investigated. Incorporation of cobalt in the form of low-spin Co³⁺ ions into the structure of hematite...
Article
The structure and electrical conductivity of iron-containing soda-lime alumino-silicate glass-ceramic system were investigated and used for the degradation of methylene blue (MB) solution. Mössbauer isomer shifts were decreased from 0.26 and 0.25 to 0.14 and 0.12 mm s⁻¹ with increasing basicity from 0.75 to 1.50 revealing the cleavage in network st...
Article
The relationship between the local structure and magnetic properties of iron phosphate glass xFe2O3 • (100-x) P2O5 abbreviated as xFeP prepared by a sol-gel method has been investigated. From the Mössbauer spectroscopy results, it was found that iron ions are present in FeIII(distorted octahedral) and FeII(octahedral) coordination. HAADF-STEM image...
Article
Pure and Cr-doped hematite (α-(Fe1-xCrx)2O3, x = 0, 0.026, 0.039, 0.085 or 0.135) nanorods were prepared by a simple co-precipitation and calcination method. Influence of different levels of Cr doping on the change of properties of long and thin pure hematite nanorods was investigated. Cr³⁺-for-Fe³⁺ substitution in the crystal structure of hematite...
Article
Designing semiconductor catalysts with superior charge carrier transfer and adequately exposed reactive sites is crucial for acquiring remarkable photocatalytic activity. Herein, a series of BiOBr catalysts with PVP as “organic armor” were synthesized via a facile precipitation strategy. As expected, the BiOBr-PVP hybrids exhibited superior catalyt...
Article
This study aims to find a suitable method to transform the amorphous iron oxides obtained from the incineration of combustible waste slag into hematite. The resulting samples were utilized as heterogeneous photocatalysts for the photo-Fenton degradation of methylene blue (MB) aqueous solution. A good correlation was found between the MB degradation...
Article
Full-text available
Ilmenite, FeTiO3, is a common mineral in nature, existing as an accessory phase in the most basic igneous and metamorphic rocks, for example, it is derived from the upper mantle. Therefore, an understanding of the high-pressure physics of FeTiO3 is of fundamental importance in the study of rock magnetization. Here, we provide experimental evidence...
Article
Glass samples with composition xFe2O3・yAl2O3・(100-x-y)SiO2 abbreviated as xFyAS for photo-Fenton catalyst were prepared by a sol-gel method and heat-treated at 1000 °C for 100 min. It was found that when alumina was added to the Fe2O3 + SiO2 glass matrix, the photo-Fenton activity tested with methylene blue degradation increased, so did the photoac...
Article
Full-text available
Fe doped FTO powders were prepared by a chemical precipitation method. Mössbauer spectra of FTO with several concentrations of Fe dopants were decomposed into two doublets (D1 and D2). A doublet with a small electric field gradient (D1) is assigned to Fe³⁺ in a small distorted site of the rutile structure, and another doublet (D2) to Fe³⁺ in a larg...
Article
Local structure and the photo-Fenton reactivity of iron-containing glasses and glass-ceramics prepared from Japanese domestic waste slag were investigated. The largest rate constant (k) of (2.8 ± 0.08) × 10⁻² min⁻¹ was recorded for the methylene blue degradation test by using H2O2 with a heat-treated ‘model slag’. The ⁵⁷Fe Mössbauer spectrum was co...
Article
The relationship between local structure and visible-light activated photocatalytic effect of simulated domestic waste slag glass–ceramics (R-NaWSFe) was investigated. The largest pseudo-first-order rate constant of 9.75 × 10⁻³ min⁻¹ was estimated for methylene blue decomposition test under the visible-light irradiation using R-NaWSFe with addition...
Article
Full-text available
57Fe Mössbauer spectra of 20BaO·3SnO2·7Fe2O3·70V2O5 glass measured at room temperature shows a marked decrease in quadrupole splitting (Δ) of iron (III) from 0.71 to 0.57 and 0.58 (± 0.02) mm s−1 after isothermal annealing at 500 °C for 30 and 60 min, respectively. The Δ value also shows a decrease from 0.71 to 0.65 and 0.60 (± 0.02) mm s−1 after t...
Article
Full-text available
Scopelophila ligulata is an Fe-hyperaccumulator moss growing in acidic environments, but the mechanism of Fe accumulation remains unknown. To understand the mechanism, we determined Fe species in S. ligulata samples. The moss samples were collected from four sites in Japan. The concentrations of Fe, P, S, Cl, and K in them were measured by induced...
Article
Vanadate glasses have numerous industrial applications and enhancement of their electrical conductivity is of interest for conducting glass for electronic and optical devices. The effect of substitutional doping of SnIV (4d¹⁰) for FeIII on the local structure and electrical conductivity (σ) of barium iron vanadate glass is investigated in this stud...
Article
Glass samples with a composition of 1.5Li2O•(1.5-x)Fe2O3•xSnO2•3P2O5 (x = 0.1, 0.3 and 0.5) were prepared by melt-quench method. X-ray diffraction (XRD) study revealed the glass formation of the as-quenched samples. Each glass sample was heat treated (HT) at 600 °C for 1 h to obtain glass ceramics. HT samples showed precipitation of a small amount...
Article
This paper systematically examines the influence of the level of Fe(III) doping on the crystal structure and other properties of Ni(OH)2. Reference β-Ni(OH)2 and Fe-doped Ni(OH)2 samples were synthesized by hydrothermal precipitation of mixed Ni(II) and Fe(III) nitrate aqueous solutions in a highly alkaline medium. The samples were investigated usi...
Article
Tin silicate glass without SnOx nanoparticles (SiO2·SnOx), a silica glass containing only SnOx nanoparticles (SiO2·SnOxNP) and the improved product, which combines the tin silicate glass with SnOx nanoparticles (SiO2·SnOx·SnOxNP) was prepared. For the structural analysis ¹¹⁹Sn Mössbauer spectroscopy and X-ray diffraction were applied. The ¹¹⁹Sn Mös...
Article
Full-text available
Fe Mössbauer spectrum of conductive barium iron vanadate glass with a composition of 20BaO·10Fe2O3·70V2O5 (in mol%) showed paramagnetic doublet peak due to distorted FeIIIO4 tetrahedra with isomer shift (δ) value of 0.37 (± 0.01) mm s⁻¹. Mössbauer spectra of 20BaO·10Fe2O3·xMoO3·(70 − x)V2O5 glasses (x = 20–50) showed paramagnetic doublet peaks due...
Article
A relationship between local structure and methylene blue degradation ability of nanoparticle (NP) mixtures composed of metallic iron (Fe⁰) and maghemite (γ-Fe2O3) was studied by means of ⁵⁷Fe-Mössbauer spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetry-differential thermal analysis (TG-DTA), ultraviolet...
Article
Full-text available
New porous ceramics (PC) prepared by recycling waste glass bottle of soft drinks (80 mass%) and bamboo charcoal (20 mass%) without any binder was applied to the waste water purification under aeration at 25 °C. Artificial waste water (15 L) containing 10 mL of milk was examined by combining 15 mL of activated sludge and 750 g of PC. Biochemical oxy...
Article
20BaO·5ZnO·5Fe2O3·70V2O5 glass annealed at 450°C for 30 min showed a marked decrease in the electric resistivity (ρ) from 4.0×10⁵ to 4.8 Ωcm, while 20BaO·5Cu2O·5Fe2O3·70V2O5 glass from 2.0×10⁵ to 5.0 Ωcm. As for the conduction mechanism, it proved that n-type semiconductor model in conjugation with the small polaron hopping theory was most probable...
Article
A relationship between the local structure and the visible-light activated photocatalytic effect was investigated in the glass and glass ceramics prepared by recycling waste slag, which was discharged from a Tokyo Household Garbage Combustion Plant. For the preparation of a homogeneous sample of waste slag recycled glass, (WSRG), 10 wt% of Na2CO3 a...
Article
The main aim of this work was to synthesize calcium phosphate silicate bioceramics by a low energy-consuming sol-gel method applying various phosphorous precursors (triethyl phosphate, phosphoric acid, and ammonium hydrogen phosphate). The investigations concentrated on the influence of phosphorous initial compounds on the bond and crystalline stru...
Article
The relationship between local structure and visible-light photocatalytic ability of tin silicate glass prepared by sol–gel method was investigated. ¹¹⁹Sn Mössbauer spectrum of SnOx·SiO2 glass prepared from SnCl2 showed a small peak of SnII component besides the major amount of SnIV. The smallest bandgap energy of 2.5 ± 0.5 eV was estimated from Ta...
Article
Indium-doped hematite samples were prepared by calcination of indium-doped goethite samples and investigated using different instrumental techniques. In³⁺-for-Fe³⁺ substitution in the hematite structure was confirmed by the determination of the unit cell expansion using X-ray powder diffraction and by the measurement of the hyperfine magnetic field...
Article
Full-text available
57Fe Mössbauer spectroscopy and XRD have successfully been applied to show the incorporation of Fe ion into the interlayer space of montmorillonite via treatment with FeCl 3 in acetone. The 78K 57Fe Mössbauer spectra of montmorillonite samples reflected magnetically split spectrum part indicating the intercalation of iron into the interlayer of mon...
Article
Full-text available
Li2O·0.25Fe2O3·0.25NiO·1.5SiO2 glass was prepared with and without 5 wt % sulfur (S) while melting the mixture of the starting materials at 1350 °C for 1 h in air. A part of the as-prepared glass was heat treated for 1 h near its crystallization temperature (Tc) as determined from differential thermal analysis. Each glass was also investigated by m...
Article
Full-text available
This paper reviews recent studies of highly conductive barium iron vanadate glass with a composition of 20 BaO · 10 Fe2O3 · 70 V2O5 (in mol %). Isothermal annealing of the vanadate glass for several ten minutes at a given temperature, higher than glass transition temperature or crystallization temperature, caused an increase in σ. Substitution of C...
Article
A relationship between structure and visible light-activated photocatalytic activity of iron-containing soda lime aluminosilicate (15Na2O⋅15CaO⋅40Fe2O3⋅xAl2O3⋅(30−x)SiO2) glass (xNCFAS) was investigated by means of 57Fe-Mössbauer spectroscopy, X-ray diffractometry (XRD) and UV–visible light absorption spectroscopy (UV–VIS). The 57Fe-Mössbauer spect...
Article
Full-text available
Egyptian basalt rock was used to prepare some glasses with different additives of Na2O by the melt quenching method. The prepared glasses were characterized applying FTIR, XRD and Mössbauer Effect (ME) spectroscopy. XRD indicated that all the samples showed a homogeneous glassy phase except the sample containing 35 mol % of Na2O which showed a very...
Article
Full-text available
A relationship between local structure, electrical conductivity (σ) and thermal property of 10SnO2·10P2O5·10Fe2O3·xAgI·(70 − x)V2O5, 10SnO2·10P2O5·10Fe2O3·xAg2O·(70 − x)V2O5 and 10SnO2·10P2O5·10Fe2O3·x/2(AgI·Ag2O)·(70 − x)V2O5 glasses, respectively abbreviated as xAIVSPF, xAOVSPF and xAIAOVSPF with ‘x’ between 0 and 40 mol % were investigated by 57...
Article
A relationship between the photocatalytic effect and the local structure of 50Fe2O3⋅ (50−x)SiO2⋅xTiO2 glass abbreviated as 50FSxTi prepared by sol-gel method was investigated by 57Fe-Mössbauer spectroscopy (FeMS), X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FT-IR) and ultraviolet-visible diffuse reflectance spectroscopy (UV...
Conference Paper
Full-text available
A relationship between local structure and methylene blue (MB) decomposing ability of nanoparticles (NPs) of metallic iron (Fe0) and maghemite (γ-Fe2O3) was investigated by 57Fe Mössbauer spectroscopy, X-ray diffractometry and UV-visible light absorption spectroscopy. γ-Fe2O3 NPs were successfully prepared by mixing (NH4)2Fe(SO4)2·6H2O (Mohr's salt...
Conference Paper
Full-text available
Heat treatment of barium iron vanadate glass, BaO-Fe2O3-V2O5, at temperatures higher than crystallization temperature causes a marked decrease in resistivity (ρ) from several MΩcm to several Ωcm. 57Fe Mössbauer spectrum of heat-treated vanadate glass shows a marked decrease in quadrupole splitting (Δ) of FeIII, reflecting a structural relaxation, i...
Article
Full-text available
Alpha iron phthalocyanines (α-FePc) oxygenated at low temperatures were investigated with the help of 57Fe Mössbauer spectroscopy, magnetization measurements (SQUID) and X-ray diffractometry (XRD). Mössbauer spectroscopy revealed that upon oxygenation of α-FePc, new species were formed which could be associated with FeIIIPc oxygen adducts. Unexpect...
Article
A relationship between local structure, thermal stability and electrical conductivity (σ) of xR2O·10Fe2O3·(90 − x)V2O5 glasses (abbreviated as xRFV glasses, where R = Li, Na, K; x = 20 and 40 in mol %) was investigated by 57Fe-Mössbauer spectroscopy, X-ray diffractometry, differential thermal analysis (DTA) and DC two- and four-probe method. From D...
Article
Full-text available
A relationship between local structure and visible light activated catalytic effect of iron containing soda lime silicate glass with the composition of 15Na2O·15CaO·xFe2O3·(70-x)SiO2, x = 5–50 mass %, abbreviated as NCFSx was investigated by means of 57Fe-Mössbauer spectroscopy, X-ray diffractometry (XRD), small angle X-ray scattering (SAXS), elect...
Article
Full-text available
The effect of firing atmosphere on the oxidation states of Fe in Arita celadon glaze and the glaze color was examined by using Mössbauer spectroscopy. The celadon glaze was prepared from feldspar, BaCO3, kaolin, α-quartz, and Fe2O3 powders and fired on the white porcelain biscuit plate at 1300°C for 0.5 h under several reduction atmospheres. The co...
Article
In this paper, we report the production of C-60[C-14] with the highest specific radioactivity to date by improving of previously reported method. To avoid the loss of C-14, the porous carbon after adsorbing C-14 labeled furan resin was sintered by "Baking" method instead of heating at 1,000 A degrees C in the electric furnace. As a result of this i...
Article
Vanadate glass is semiconductive with the electrical conductivity(σ) of 10−7 - 10−5 S cm−1, which is caused by 3d electron(polaron) hopping from VVI(or VIII) to VV. Interestingly, a drastic increase of σ from 10−5 to 100 S cm−1 was observed when 20BaO·70V2O5·10Fe2O3 glass was isothermally annealed at around crystallization peak temperature(Tc) of 5...
Article
Vanadate glass is semiconductive with the electrical conductivity(σ) of 10−7 - 10−5 S cm−1, which is caused by 3d electron(polaron) hopping from VVI(or VIII) to VV. Interestingly, a drastic increase of σ from 10−5 to 100 S cm−1 was observed when 20BaO·70V2O5·10Fe2O3 glass was isothermally annealed at around crystallization peak temperature(Tc) of 5...
Article
In this review, we introduce a relationship between the local structure and visible light activated photocatalytic effect of two types of iron containing silicate glasses, i.e., 15Na2O·15CaO·xFe2O3·(70-x)SiO2 glass (x = 10-50 in mass %, abbreviated as xNCFS) prepared by melt quenching method and xFe2O3·(100-x)SiO2 giass (x = 10-50 in mass %, abbrev...
Article
In this chapter, relationships between local structure and organic compounds decomposing ability of Fe0 + γ-Fe2O3 mixture were introduced by applying gas chromatography (GC), ultraviolet-visible light absorption spectroscopy (UV-VIS), electrospray-ionized mass spectroscopy (ESI-MS), X-ray diffractometry (XRD) and 57Fe-Mössbauer spectroscopy. Decrea...
Article
In the present work, significantly various structures connected by Al-O/OH/acetate-Al bonds were synthesized in a versatile sol-gel route. The various bond systems result in several three-dimensional (e.g., fibrous, highly porous, and compact) macrostructures. The shared acetate and OH ions provide the fibrous character; the shared OH ions and oxyg...
Chapter
Mössbauer spectroscopy is quite effective for the research and development of advanced materials that can contribute for the solution of resource, energy, and environmental issues.Most oxide glass has a three-dimensional network structure composed of network former (NWF), such as SiO2, B2O3, P2O5 and network modifier (NWM) such as Na2O, K2O, CaO, a...
Chapter
This chapter described on the recycling process of iron-containing “waste” of silicate glasses that are very effective for the purification of polluted water. The studies proved that iron-containing “waste” of silicate glasses had an interesting electromagnetic phenomenon. The chapter focuses on recycling of combustion ash, discarded from a municip...
Article
Novel iron(II) oxime complexes with dimethyl-glyoxime, methyl-ethyl-glyoxime, methyl-isopropyl-glyoxime, [Fe(DioxH)2L2] with and without axial ligands have been synthesized. 57Fe Mössbauer spectroscopy showed different spin states in complexes with short alkyl chain and with branched alkyl chain, respectively. It was shown that the asymmetry observ...
Article
Full-text available
Glass sample with a composition of Li1.3Nb0.3Fe1.7(PO4)3, prepared by a conventional melt-quenching method, was heat treated to obtain glass ceramics of NASICON type. Glass transition (T g) and crystallization (T c) temperatures of as-quenched glass sample were determined by differential thermal analysis (DTA). X-ray diffraction (XRD) patterns also...
Article
Charge-discharge capacity and cyclicity of lithium ion battery (LIB) was evaluated in which 15Li2O·10Fe2O3·xSnO2·5P2O5·(70–x)V2O5 glass (x = 0 and 20 in mol%, abbreviated as xLFSPV) was used as a cathode. A local structure of xLFSPV glass before and after charging was investigated by 57Fe- and 119Sn-Mössbauer spectroscopies. 57Fe-Mössbauer spectrum...