Titanium dioxide is a well known material for its photocatalytic properties, but its major defect is its energy activation range. Due to its band gap energy, it can only be activated by ultraviolet light which limits its applications. Moreover the sputtered titanium dioxide coatings often present a lower photocatalytic activity regarding with other processes such as sol-gel method which allows the synthesis of very porous layers. Extensive efforts have been realised by several authors to develop titania coatings that can use solar or indoor light and which present a better quantum yield (or photocatalytic response to the light activation).

In this paper, we study the effect of addition elements (Ag, N, Fe, La, Na...) in titania coatings on their chemical, physical and photocatalytic properties. The coatings are synthesised by reactive magnetron sputtering on soda-lime glass. The titania doping is carried out either by using a second metallic target simultaneously sputtered with titanium or by introducing nitrogen in combination with oxygen. In all cases, a diffusion barrier layer is previously deposited to prevent the coatings poisoning by the sodium of glass.

In a first part, we investigate the coatings structure by X-ray diffraction, as well as their morphology and microstructure by scanning and transmission electron microscopy, as a function of the doping element content, measured either by energy dispersive spectroscopy or by electron energy loss spectroscopy for the lighter elements. The optical properties of the films are also determined by means of NUV-visible-NIR spectroscopy. The second part is ascribed to the photocatalytic activity measurements under UV irradiation. The tests are been performed in water containing organic compounds considered as model polluants (e.g. orange II). Finally, the photocatalytic properties are discussed in relation with the films composition, microstructure and morphology.