| abstract |
(1) A precursor containing a copper compound having a specific molar ratio of titanium to copper (Ti / Cu) from a raw material titanium compound, a copper compound, a basic substance, hydrogen peroxide, and an aqueous dispersion medium. A step of producing an aqueous solution, and (2) a step of heating the precursor aqueous solution containing the copper compound produced in the step (1) in a predetermined range under high pressure to obtain a copper-containing titanium oxide fine particle dispersion. A method for producing a visible light responsive photocatalyst fine particle dispersion in which titanium oxide fine particles containing a peroxotitanium component and a copper component are dispersed in an aqueous dispersion medium obtained by the method. [Effect] Excellent long-term dispersion stability of titanium oxide fine particles in an aqueous dispersion medium without the addition of organic dispersants or surfactants that inhibit photocatalytic activity and surface treatment of titanium oxide particles. Further, a photocatalytic thin film that exhibits photocatalytic activity only with visible light, has high transparency, is stable in the coordination state of copper with respect to exposure to heat and ultraviolet rays, is not easily denatured, and has high durability can be easily produced. [Selection figure] None |