TITANIUM-MANGANESE OXIDES. OPTICAL AND PHOTOCATALYTIC PROPERTIES

Nanocrystalline titanium-manganese mixed oxides (TMO)with the Mn content of 1316 % at. were first synthesized by manganese hydroxide precipitation on anatase or rutile particles. The structure, morphology and chemical composition of the samples were characterized using XRD and XRF methods showing that the synthesized mixed oxides are the polydisperse materials of different phase composition containing TiO2, Mn2O3 and MnTiO3. The phase transformations and structure defects of the prepared compounds were characterized by FTIR, FT-FIR, FT-Raman spectroscopies. UV-VIS absorption spectra were investigated in 2,4-6,0 eV region, and it was revealed that the presence of manganese oxides results in absorption increase and significant red shift of the TMO absorption edge in comparison with pure TiO2. Photocatalytic activity of pure TiO2, Mn2+-doped TiO2 and TMO during the photocatalytic decomposition of the safranine dye under UV irradiation was studied. A great improvement of photocatalytic activity is registered for Mn2+-doped TiO2 (anatase and rutile), and rutilebased TMO sample.