CVD of TiO2 and TiO2/Ag antimicrobial layers: Deposition from the hexanuclear μ-oxo Ti(IV) complex as a precursor, and the characterization

Hexanuclear μ-oxo titanium(IV) complex, of the general formula [Ti6O6(H2O)2(OiBu)6(O2CtBu)6], has been used as a new type of TiO2 chemical vapor deposition precursor. Thin titanium dioxide layers of a different polymorphic structure were grown on the surface of titanium foil or titanium surgical implants, as substrates, in a wide range of substrate temperatures 693–853 K, under Ar atmosphere. The best antimicrobial activity revealed TiO2 covers deposited between 713 and 733 K. Loose packing layers produced at 733 K were doped by silver grains by CVD method using silver(I) 3,3-dimethyl tert-butyrate complex with triethylphosphane as a precursor. The increase of the antimicrobial activity of TiO2–Ag system with the increase of Ag grains content was noticed. Crystallinity, composition, and morphology of TiO2 and TiO2/Ag layers were analyzed by X-ray diffraction method, high resolution transmission electron microscopy, and scanning electron microscopy.

► Thin TiO2 films were grown by CVD method using a new type of a precursor. ► TiO2/Ag coatings with ~ 1%–~ 4% metallic silver dopant, were produced. ► Titanium implants have been used as substrates. ► Crystallinity, composition, and morphology of TiO2 and TiO2/Ag films are analyzed. ► Microbiocidal properties of TiO2 and TiO2/Ag thin layers are discussed.