Self-cleaning properties of nanocrystalline TiO2 thin films doped with terbium

Abstract

In this work photocatalytic activity of transparent TiO2 coatings doped with Tb was described. Thin films were performed by high energy reactive magnetron sputtering process. During deposition, particles were sputtered from metallic Ti and Ti-Tb targets in oxygen reactive plasma. The properties of thin films were characterized by several methods. Influence of Tb-dopant on the structure and diversification of the surface was investigated by X-ray Diffraction and Atomic Force Microscopy, respectively. Optical properties of manufactured films, especially transparency level and adsorption edge, were determined based on optical transmission measurements. Photocatalytic activity of TiO2:Tb thin films was determined based on phenol decomposition reactions under UV-Vis light exposure. The rate of phenol decomposition was determined based on absorption measurements. The results have shown that all manufactured films were nanocrystalline and photocatalytically active. Doping with terbium meaningfully increased the activity of as-deposited films. In this paper dependences between structure type of the TiO2-matrix, crystallites size, roughness of the thin film surface and photocatalytic activity of TiO2:Tb thin films are described. Especially, the key-role of terbium on properties of TiO2 matrix is discussed.