Process for the production of photocatalytic coatings on substrates

A process for the production of a photocatalytically active coated substrate comprising depositing on the glass substrate surface a layer of photocatalytically active titanium oxide characterized in that it has a thickness of less than 40 nm by contact with the surface of the substrate, which is at a temperature in the range of 645 ° C to 720 ° C, with a fluid mixture that has the source of titanium.