The Influence of Nd and Sm on the Structure and Properties of Sol-Gel-Derived TiO<sub>2</sub> Powders
Albena Bachvarova-Nedelcheva,
Stancho Yordanov,
Reni Iordanova,
Irina Stambolova,
Angelina Stoyanova,
Nelly Georgieva,
Veronica Nemska
Affiliations
Albena Bachvarova-Nedelcheva
Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev str., bld. 11, 1113 Sofia, Bulgaria
Stancho Yordanov
Institute of Metal Science, Equipment and Technologies “Acad. A. Balevski” with Center for Hydro- and Aerodynamics at the Bulgarian Academy of Sciences, 67 Shipchenski prohod str., 1574 Sofia, Bulgaria
Reni Iordanova
Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev str., bld. 11, 1113 Sofia, Bulgaria
Irina Stambolova
Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev str., bld. 11, 1113 Sofia, Bulgaria
Angelina Stoyanova
Department Chemistry and Biochemistry, Faculty of Pharmacy, Medical University—Pleven, Kl. Ohridski str., 1, 5800 Pleven, Bulgaria
Nelly Georgieva
Department Biotechnology, Faculty of Chemical and Systems Engineering, University of Chemical Technology and Metallurgy, Kl. Ohridski Blvd, 8, 1756 Sofia, Bulgaria
Veronica Nemska
Department Biotechnology, Faculty of Chemical and Systems Engineering, University of Chemical Technology and Metallurgy, Kl. Ohridski Blvd, 8, 1756 Sofia, Bulgaria
TiO2 nanopowders modified by Nd and Sm were prepared using the sol-gel technique. It was found by XRD analysis that the samples containing Sm are amorphous up to 300 °C, while those with Nd preserve a mixed organic-inorganic amorphous structure at higher temperatures (400 °C). The TiO2 (rutile) was not detected up to 700 °C in the presence of both modified oxides. TiO2 (anatase) crystals found at about 400 °C in the Sm-modified sample exhibited an average crystallite size of about 25–30 nm, while doping with Nd resulted in particles of a lower size—5–10 nm. It was established by DTA that organic decomposition is accompanied by significant weight loss occurring in the temperature range 240–350 °C. Photocatalytic tests showed that the samples heated at 500 °C possess photocatalytic activity under UV irradiation toward Malachite green organic dye. Selected compositions exhibited good antimicrobial activity against E. coli K12 and B. subtilis.
