Author
Ryusaburo Furuichi
Bio: Ryusaburo Furuichi is an academic researcher from Hokkaido University. The author has contributed to research in topics: Oxide & Thermal decomposition. The author has an hindex of 21, co-authored 103 publications receiving 1492 citations.
Topics: Oxide, Thermal decomposition, Ion exchange, Adsorption, Anodizing
Papers published on a yearly basis
Papers
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TL;DR: It is shown that all hydroxyl groups take part in ion exchange and that the unusually small values reported elsewhere with the saturated (de)protonation method may contain errors.
206 citations
TL;DR: In this paper, the Frumkin isotherm was used to model the reaction of metal oxides to maintain electric neutrality in water by adsorption, and the amount of surface charge in alkali metal nitrate solutions was measured as a function of pH.
Abstract: Metal oxides abundant in natural environments affect the concentrations of ions in waters by adsorption. The ion adsorption ability of oxides arises from the acid−base nature of surface hydroxyl groups formed by dissociative chemisorption of water molecules. The protonation and deprotonation reactions of hydroxyl groups produce electric charges, resulting in ion adsorption to maintain electric neutrality (ion exchange). The amount of surface charge in alkali metal nitrate solutions was measured as a function of pH by titration, and the ion-exchange reactions accompanying the charge formation were modeled by using the Frumkin isotherm, which assumes suppression of the reaction due to lateral interactions between the interphase species. This model embodies not only electrical but also chemical, geometrical, and/or other lateral interactions and can be applied to “real”, not well-defined oxide/solution systems in natural environments. From the model parameters, it was found that the intensity of cation excha...
95 citations
01 Nov 1997
TL;DR: It was found that the Co2+ adsorption ability of metal oxides increases in the order Al2O3 < Fe2 O3 < TiO2 < Fe3O4 < MnO2, showing a good correlation to the electronegativity Xi of the lattice metal ions of the oxides.
Abstract: Adsorption of Co(II) ions on metal oxides is related to radioactive60Co(II) (de)contamination of nuclear power plants, Co(II) ion retention in soils as a plant nutrient, concentration of Co(II) in deep-sea manganese nodules, and other applications. Here, the amount of adsorbed Co(II) on metal oxides was measured as a function of the pH and concentration of Co(II) ions, and the adsorption properties of metal oxides were evaluated with a model that considers simultaneous (1:1) and (1:2) exchange reactions between Co2+aqua ions and surface hydroxyl protons obeying the Frumkin isotherm. The possibility of participation of mono- and polynuclear Co(II) hydroxo complexes in the adsorption was examined, and it was suggested that these species play no role under the conditions here. From the model parameters, it was found that the Co2+adsorption ability of metal oxides increases in the order Al2O3
70 citations
TL;DR: In this paper, the influence of the preparation history of α-Fe2O3 on its reactivity has been investigated in the context of hydrogen reduction of the metal ion Cu2+, Ni2+, and Ti4+ in a stream of oxygen, air or nitrogen at temperatures of 500-1200°C for one hour.
66 citations
TL;DR: In this article, the composition and structure of the oxide were determined by X-ray photoelectron spectroscopy (XPS) and x-ray diffraction (XRD).
60 citations
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Book•
01 Jan 1971
TL;DR: In this paper, Ozaki et al. describe the dynamics of adsorption and Oxidation of organic Molecules on Illuminated Titanium Dioxide Particles Immersed in Water.
Abstract: 1: Magnetic Particles: Preparation, Properties and Applications: M. Ozaki. 2: Maghemite (gamma-Fe2O3): A Versatile Magnetic Colloidal Material C.J. Serna, M.P. Morales. 3: Dynamics of Adsorption and Oxidation of Organic Molecules on Illuminated Titanium Dioxide Particles Immersed in Water M.A. Blesa, R.J. Candal, S.A. Bilmes. 4: Colloidal Aggregation in Two-Dimensions A. Moncho-Jorda, F. Martinez-Lopez, M.A. Cabrerizo-Vilchez, R. Hidalgo Alvarez, M. Quesada-PMerez. 5: Kinetics of Particle and Protein Adsorption Z. Adamczyk.
1,870 citations
TL;DR: In this article, the progress that has taken place since 1993 with regard to film deposition, characterization by physical and chemical techniques, optical properties, as well as electrochromic device assembly and performance is reviewed.
1,304 citations
TL;DR: In this paper, the mechanism of different catalysts in the catalytic peroxymonosulfate (PMS) solution was illustrated, and the results showed that the incorporation of CoFe 2 O 4 had the highest catalytic performance in PMS oxidation for DBP degradation.
Abstract: Magnetic ferrospinel MFe 2 O 4 (M = Co, Cu, Mn, and Zn) prepared in a sol–gel process was introduced as catalyst to generate powerful radicals from peroxymonosulfate (PMS) for refractory di-n-butyl phthalate (DBP) degradation in the water. Various catalysts were described and characterized, and the catalytic activities in PMS oxidation system were investigated. Most important of all, the mechanism of different catalysts in the catalytic PMS solution was illustrated. The results showed that the incorporation of CoFe 2 O 4 had the highest catalytic performance in PMS oxidation for DBP degradation. All catalysts presented favorable recycling and stability in the repeated batch experiment. The catalytic process showed a dependence on initial pH, and an uncharged surface of the catalyst was more profitable for sulfate radical generation. H 2 -TPR and CVs analysis indicated that the sequence of the catalyst's reducibility in PMS solution was CoFe 2 O 4 > CuFe 2 O 4 > MnFe 2 O 4 > ZnFe 2 O 4 , which had a close connection with the activity of metal ion in A site of the catalysts. The surface hydroxyl sites played an important role in the catalytic process, and its quantity determined the degradation of DBP. Moreover, the reactive species in PMS/MFe 2 O 4 system were identified as sulfate radical and hydroxyl radical. The promotion of these radical's reaction was due to the fact that a balance action in the process of M 2+ /M 3+ , O 2− /O 2 , occurred, and at the same time, PMS was catalyzed.
776 citations
638 citations
TL;DR: In this article, the XPS coherent binding energy (BE) data basis for reference compounds that are representative of oxidation products formed onto the pyrite reactive surface was presented, and the data in BEs obtained from reference compounds have been exploited to show the surface species of an oxidized pyritic in a HCO3−2 M medium.
632 citations