| 摘要 |
This invention aims to provide a method for producing a crystalline titanium oxide film that is suitable for industrial production; that forms a large amount of crystalline titanium oxide; and that is useful as a photocatalyst, a photovoltaic element, and the like. Such a crystalline titanium oxide film is produced through the following steps (a-1) and (b) : (a-1) a step of heating titanium or titanium alloy under either of the following conditions (1) to (3) to form titanium nitride on the surface of the titanium or titanium alloy; (1) in an atmosphere of nitrogen and/or ammonia gas in the presence of an oxygen trapping agent; (2) in an atmosphere where a pressure is reduced to discharge atmospheric gas, and then nitrogen and/or ammonia gas are/is introduced; or (3) in an atmosphere where a pressure is reduced to discharge atmospheric gas, and then nitrogen and/or ammonia gas are/is introduced in the presence of oxygen trapping agent; and (b) a step of immersing the titanium or titanium alloy obtained in step (a-1) above in an electrolyte containing an inorganic acid and/or organic acid, and applying voltage for anodization. |
