Ken-ichi Katsumata

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Porous ceramics with unidirectionally oriented pores have been prepared by various methods such as anodic oxidation, templating using wood, unidirectional solidification, extrusion, etc. The templating method directly replicates the porous microstructure of wood to prepare porous ceramics, whereas the extrusion method mimics the microstructures of tracheids(More)
Novel visible-light-driven graphitic carbon nitride (g-C₃N₄)/WO₃ composite photocatalysts were prepared, and the acetaldehyde (CH₃CHO) degradation activity of these composites was evaluated. The prepared g-C₃N₄/WO₃ composites were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM),(More)
Brookite TiO(2) nanoparticles with amphiphilic properties were successfully synthesized with a water-soluble titanium glycolate complex precursor using an oleate-modified hydrothermal growth process. The ~20-40 nm TiO(2) nanoparticles were highly dispersible in both water and cyclohexane. The activity of the brookite nanoparticles for the degradation of(More)
NaNbO(3) thin films prepared by the sol-gel method had homogeneous microstructure with an average grain size of 15-25 nm and exhibited photoinduced hydrophilic conversion under UV irradiation. However, the films had little photocatalytic oxidation activity under UV irradiation. This is the first observation that NaNbO(3) undergoes photoinduced(More)
Selection of the excitation wavelength at nonresonant and resonant Raman conditions provided detection selectivity in the tetragonal and cubic phases in CeO(2)-ZrO(2) nanocrystals, respectively. It was suggested that cubic-phase domains containing Ce(3+) deficiencies were involved in the tetragonal-phase matrix.
The inactivation of Escherichia coli and Qβ phage was examined following their photocatalytic treatment with TiO2 hollows and spheres that had been prepared by electrospray, hydrothermal treatment, and calcination. The crystal structures of the hollows and spheres were assigned to TiO2 anatase, and the surface areas of the hollows and spheres were(More)
A novel photocatalyst consisting of an intercalated perovskite H(1-2x)Pt(x)LaNb2O7 was fabricated by ion exchange. Synchrotron X-ray diffraction and X-ray photoelectron spectroscopy results confirmed that Pt(2+) exists within the interlayer space of the layered perovskite. H(1-2x)Pt(x)LaNb2O7 composed of layered niobate perovskite and intercalated Pt(2+)(More)
Transparent ZnO were prepared using solutions with various trisodium citrate concentrations by a spin-spray method at 90°C. The morphological and structural characteristics, as well as photocatalytic activity of the resulting ZnO films were examined with respect to the added trisodium citrate concentration. Photocatalytic activities of the ZnO films were(More)
Titanium dioxide thin films were prepared by using four water-soluble titanium complexes of titanium-lactate, tartalate, malate and salicylate complex solutions. The crystalline phases detected in the films were anatase. The surface microstructures of the four film samples were different in their grain sizes. Photocatalytic decomposition activity of the(More)
TiO2-supported activated carbon felts (TiO2-ACFTs) were prepared by dip coating of felts composed of activated carbon fibers (ACFs) with either polyester fibers (PS-A20) and/or a polyethylene pulp (PE-W15) in a TiO2 aqueous suspension followed by calcination at 250 °C for 1 h. The as-prepared TiO2-ACFTs with 29-35 wt.% TiO2 were characterized by X-ray(More)