Patent ID: 7985443

Claim:
A process for manufacturing a lighting device comprising a light source and a wall that lets at least a portion of the radiation emitted by a source pass therethrough, said wall having a coating over at least a portion of at least one of its two faces of a photocatalytically active layer, wherein under the lowest illumination conditions, the photocatalytic activity of said layer degrades the organic soiling and reduces said soiling to particles that do not adhere to said layer and can be easily removed therefrom, and/or to give said layer a hydrophilic character, wherein said process comprises forming said photocatalytically active layer as a mesoporous structure by a sol-gel method comprising: preparing a liquid composition comprising at least one precursor of an essentially mineral material constituting the mesoporous structure of said layer and at least one organic structuring agent; precipitating the precursor around the organic structuring agent and growing molecules derived from the precursor; adding into the liquid composition elementary crystallites or nanoparticles of optionally doped titanium oxide, with diameters between 0.5 and 100 nm; applying the composition to the surface to be coated; and eliminating the organic structuring agent, the titanium oxide crystallites being incorporated into the mesoporous structure while essentially maintaining their integrity.