In the present work, titanium dioxide thin layers were prepared using anodic oxidation. Different structures were obtained and were modified by cerium electrodeposition. The aim of the study was to find the best conditions in order to improve the photocatalytic properties which were measured under UV-A light with two pollutants: methanol and the black amido dye. The photo-electrochemical results show that the photo-activity is improved when cerium is present in the layer, with a Ce/Ti ratio close to 0.6 atom%. This is due to a better separation of photogenerated electron-hole pairs. The layers with nanotube-array were obtained through anodisation of titanium at 20V, during 45 min in three different electrolytes: a mixture of ethylene glycol-ammonium fluoride and water (NT1), a mixture of tetrabutylammonium fluoride-formamide (NT2), and a mixture of sodium sulphate-ammonium fluoride and water (NT3). Photocatalytic results showed that the degradation of dye proceeds much faster in the presence of NT1. This result is attributed to the higher specific surface and higher solid fraction, which improve the absorption of incident light. Moreover in NT1 the rate of charge recombination is assumed to be lowest.
