N- and N, C-Doped TiO2 Powders and Their Visible Light Activity
(EN)
Todorova, N.
(EN)
Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείας
(EL)
Todorova, N.
(EN)
TiO2 powder was synthesized via sol-gel technique. Nitrogen (N) and carbon (C) doped TiO2 powders were prepared applying: (a) thermal treatment of the prepared TiO2 with N, C precursor urea (U); (b) synthesis of TiO2 in presence of N, C containing substance triethylamine (TEA). According to the XPS results the U-modification led to interstitial incorporation of N into TiO2 lattice. The C was found as organic impurities in quantity compatible to that of unmodified TiO2. The addition of TEA to the initial solution resulted in enhanced interstitial N-doping and detention of larger quantity C. The major part of the C was found as organic impurities and a small amount was detected as dopant. The UV-Vis diffuse reflectance spectra demonstrated slight red shift of the main absorption and enhanced absorption between 400-500 nm for the U-modified TiO2. The TEA modification resulted in increased absorption in the entire visible part of the spectrum and decreased band gap value 2.89 eV. However, the photocatalytic activity of this sample was extremely low under both UV and visible light. The U-modified TiO2 exhibited improved activity under visible light in comparison to unmodified TiO2.
(EN)
