Lanthanide-doped titanium dioxide layers as photocatalysts

Films (similar to 0.5 mg/cm(2)) from TiO2 doped with 1-10 mol% Ln(3+) (Ln = La or Gd) are deposited on different types of substrates by spray-pyrolysis using ethylene glycol solutions of Ti4+-Ln(3+) citric complexes as starting material and O-2 as a carrier gas. The films are post-deposition heated at 500 degrees C. Their phase composition, crystal structure, morphology, sorption ability and photocatalytic activity are studied. Aqueous solution of methylene blue is applied as a model pollutant. A film with 5 mol% La on Ti-coated stainless steel substrate shows significantly higher photocatalytic activity than the best performing samples produced from commercially available titania. (C) 2008 Elsevier B.V. All rights reserved.