Influence of Eu-doping on wettability of TiO2 thin films

In this work nanocrystalline titanium dioxide thin films doped with Eu have been presented. Structural investigation results have shown that amount of Eu in TiO₂ matrix has meaningful influence on properties of the thin films, particularly on TiO₂ phase and grain sizes. Our measurements have shown that Eu increases photocatalytic activity of TiO₂. Eu also has high influence on adsorption of OH- groups and H₂O particles on the thin films surface. The results of wettability measurements have shown that 0.1 at.% of Eu-dopant in TiO₂ matrix allows to obtain hydrophilic anatase structure, which is stable up to 800degC. The wettability of nanocrystalline TiO₂:Eu (0.1 at.%) thin film also increase with the increase of temperature during additional annealing. The value of wetting angle of TiO₂:Eu (0.1% at.) thin film decrease at about 40% by additional annealing up to 800degC (from 85 down to 68 degrees). The increase of the wettability of the TiO₂:Eu (0.1 at.%) thin film by additional annealing was also connected with decrease of quantity of OH- groups and H₂O particles, which were adsorbed on the thin film surface.