Process for the preparation of articles in Titanium coated with a thick layer of anastase, articles so obtainable, and use thereof as photocatalysts

Process for the preparation of articles in Titanium coated with a layer of Titanium oxide is described, wherein the metallic Titanium is subjected to the following steps: optional conditioning of the surface; anodic oxidation treatment, in an electrolytic cell of which it represents the anode, in a bath made of an aqueous solution comprising sulfuric acid, hydrochloric acid and hydrofluoric acid; and forming onto the metallic surface, by effect of electrolysis, an oxide layer having a >1 m thickness and containing a single crystalline phase made of anatase (one of the two allotropic tetragonal shapes of Titanium oxide). Object of the invention are also the articles in Titanium coated with a thick layer of anatase so obtainable, and the use thereof as photocatalysts, under the action of an ultraviolet radiation.