Abstract: In a formulation comprising titanium dioxide as a photocatalyst and an amphoteric metal oxide (alumina or the like) or a basic metal oxide (barium oxide, strontium oxide or the like) as a material having a base point, when a nitrogen oxide (nitrogen monoxide) comes into contact with or approaches titanium dioxide, upon exposed to light, the carbon monoxide is oxidized to nitrogen dioxide (gas) by hydroxy radicals as an active oxygen species produced by titanium dioxide. As is apparent from the molecular structure, nitrogen dioxide is an acidic gas, alumina is an amphoteric metal oxide, and barium oxide and strontium oxide are a basic metal oxide. The oxygen atom thereof serves as a base point to an acid gas. Therefore, nitrogen dioxide is attracted and chemically bonded to the oxygen atom, held on the metal oxide, and kept close to titanium dioxide as the photocatalyst.

Abstract: A composite material includes a substrate and a self-cleanable hydrophilic surface layer. The surface layer includes a plurality of components: a first component having a photocatalyst which functions as a catalyst upon exposure to light; a second component having one or more of aluminum oxide, zinc oxide, strontium oxide, barium oxide, magnesium oxide, calcium oxide, rubidium oxide, sodium oxide, potassium oxide and phosphorus pentoxide; and a third component having one or more of silicon dioxide, zirconium dioxide, germanium dioxide and thorium dioxide. The first through third components are all situated within the surface layer, which is provided as a single surface layer, such that all of the components are in close proximity to one another within the single surface layer.

Abstract: A composite material includes a substrate and a self-cleanable hydrophilic surface layer. The surface layer includes a plurality of components: a first component having a photocatalyst which functions as a catalyst upon exposure to light; a second component having one or more of aluminum oxide, zinc oxide, strontium oxide, barium oxide, magnesium oxide, calcium oxide, rubidium oxide, sodium oxide, potassium oxide and phosphorus pentoxide; and a third component having one or more of silicon dioxide, zirconium dioxide, germanium dioxide and thorium dioxide. The first through third components are all situated within the surface layer, which is provided as a single surface layer, such that all of the components are in close proximity to one another within the single surface layer.

Abstract: In a formulation comprising titanium dioxide as a photocatalyst and an amphoteric metal oxide (alumina or the like) or a basic metal oxide (barium oxide, strontium oxide or the like) as a material having a base point, when a nitrogen oxide (nitrogen monoxide) comes into contact with or approaches titanium dioxide, upon exposed to light, the carbon monoxide is oxidized to nitrogen dioxide (gas) by hydroxy radicals as an active oxygen species produced by titanium dioxide. As is apparent from the molecular structure, nitrogen dioxide is an acidic gas, alumina is an amphoteric metal oxide, and barium oxide and strontium oxide are a basic metal oxide. The oxygen atom thereof serves as a base point to an acid gas. Therefore, nitrogen dioxide is attracted and chemically bonded to the oxygen atom, held on the metal oxide, and kept close to titanium dioxide as the photocatalyst.

Abstract: A hydrophilic material comprises a substrate and a hydrophilic layer provided as the outermost layer on the substrate. The hydrophilic layer comprises hydrophilic metal oxide particles and a hydrophilic inorganic amorphous material. The hydrophilic layer has profile peaks on its surface. The hydrophilic layer has roughness properties such that, when a segment is set in only a portion not containing the profile peaks, the ten-point mean roughness (Rz) and the mean distance between concaves and convexes (Sm) obtained from a profile curve in the segment are 10 nm≦Rz≦40 nm and 10 nm≦Sm≦300 nm, respectively, while, when a segment is set so as to pass through the profile peaks, the ten-point mean roughness (Rz) and the mean distance between concaves and convexes (Sm) obtained from a profile curve in the segment are 40 nm≦Rz≦200 nm and 300 nm≦Sm≦500 nm, respectively.

Abstract: In a formulation comprising titanium dioxide as a photocatalyst and an amphoteric metal oxide (alumina or the like) or a basic metal oxide (barium oxide, strontium oxide or the like) as a material having a base point, when a nitrogen oxide (nitrogen monoxide) comes into contact with or approaches titanium dioxide, upon exposed to light, the carbon monoxide is oxidized to nitrogen dioxide (gas) by hydroxy radicals as an active oxygen species produced by titanium dioxide. As is apparent from the molecular structure, nitrogen dioxide is an acidic gas, alumina is an amphoteric metal oxide, and barium oxide and strontium oxide are a basic metal oxide. The oxygen atom thereof serves as a base point to an acid gas. Therefore, nitrogen dioxide is attracted and chemically bonded to the oxygen atom, held on the metal oxide, and kept close to titanium dioxide as the photocatalyst.