The influence of alizarin and fluorescein on the photoactivity of Ni, Pt and Ru-doped TiO2 layers

The doping with different metal ions and sensitization with organic compounds are two well known methods used to improve the photoactivity of TiO2. In this respect, the metallic ions-doped TiO2 samples were prepared by embedding Ni, Pt and Ru ions into TiO2 crystalline network and then, each sample was sensitized with alizarin and fluorescein dyes. The qualitative evaluation of prepared TiO2-based materials was made by: UV–vis spectroscopy, spectrofluorimetry, FT/IR spectroscopy and microscopy, X-ray diffraction and N2 physisorption measurements. The optoelectronic properties investigated by UV–vis spectroscopy show that the optical response of Ni-doped TiO2 layer shifts to visible. The X-ray spectra do not show peaks of nickel, platinum and ruthenium oxide crystals or pure metals. The FT/IR spectra proved the presence of dye molecules adsorbed on titania nanoparticles surface. These results demonstrated that the studied dopants and dyes have potential to promote modified TiO2-based materials as good candidates to be used in photolectrocatalytic processes.