Synthesis of Disk-Shaped Tungsten(VI) Oxide Particles with Various Physical Properties for Mineralization of Acetic Acid in Water Under Irradiation of Visible Light.

Disk-shaped tungsten(VI) oxide (D-WO₃) particles were synthesized according to a previously reported method consisting of pyrolysis, precipitation, and calcination, and the calcination temperature was changed (200-600 °C). The samples were characterized by field-emission scanning electron microscopy, transmission electron microscopy, powder X-ray diffraction, the Brunauer- Emmett-Teller single-point method, and diffuse reflectance spectroscopy. In addition, to evaluate the photocatalytic activities of the samples, the mineralization of acetic acid to carbon dioxide (CO₂) was measured by loading Pt particles onto the surface of the samples by photodeposition and irradiating them in an aqueous suspension with a blue light-emitting diode.

Preparation of Ni nanoparticles by liquid-phase reduction to fabricate metal nanoparticle-polyimide composite films.

Nickel-nanoparticle-containing polyimide composite films were prepared by liquid-phase reduction of Ni ions with potassium borohydride (KBH). The nanoparticles were amorphous with diameters of approximately 10-20 nm, depending on the KBH concentration and reduction temperature. At high KBH concentrations, the nanoparticles appeared to contain various nickel boride species.