Abstract: The object of the present invention is to provide a method of producing low valence titanium oxides in a steady supply manner acceptable in industrial production. The low valence titanium oxides are produced by electrical discharge between two electrodes in an aqueous medium, wherein at least one of the electrodes is a titanium-containing electrode.

Abstract: A method of producing a Group II-VI compound semiconductor. The method involves generating a pulsed electrical discharge plasma between metallic electrodes in sulfur to produce a Group II-VI compound semiconductor. A method of producing a Group II-VI compound semiconductor phosphor using a pulsed electrical discharge plasma. A hexagonal crystal of Group II-VI compound semiconductor composed of a plurality of twin crystals.

Abstract: The object of the present invention is to provide a method of producing low valence titanium oxides in a steady supply manner acceptable in industrial production. The low valence titanium oxides are produced by electrical discharge between two electrodes in an aqueous medium, wherein at least one of the electrodes is a titanium-containing electrode.

Abstract: An object is to provide a novel anatase titanium oxide having especially high photocatalytic activity as a photocatalyst useful as a material for environmental clean-up, such as removal of toxic substances, deodorization and decomposition of malodorous substances, prevention of fouling and sterilization, and a method of producing such an anatase titanium oxide. There is provided a titanium oxide having a reflectance of 80% or lower with respect to light having a wavelength of 400 nm to 700 nm. There is also provided a method of producing an anatase titanium oxide, comprising creating pulsed plasma by an electric current of lower than 5 amperes between titanium electrodes in water to oxidize a titanium. Preferably, the titanium oxide has a percentage weight loss of 1.0% or lower when heated at a temperature within the range of 400° C. to 800° C., and has the anatase structure or the anatase and rutile structures.

Abstract: An object of the invention is to provide a method for the stable production of a high-purity Group II-VI compound semiconductor on an industrial scale, and also a hexagonal crystal of Group II-VI compound semiconductor in which a metal can be doped easily. Another object of the invention is to provide a method of producing a Group II-VI compound semiconductor phosphor. The objects are achieved by a method of producing a Group II-VI compound semiconductor comprising generating a pulsed electrical discharge plasma between metallic electrodes in sulfur to produce a Group II-VI compound semiconductor; a method of producing a Group II-VI compound semiconductor phosphor using a pulsed electrical discharge plasma; and a hexagonal crystal of Group II-VI compound semiconductor composed of a plurality of twin crystals.