Characterization of Photoactive Fe-TiO(2) Lime Coatings for Building Protection: The Role of Iron Content

Iron-doped TiO(2) nanoparticles, ranging in Fe concentrations from 0.05 up to 1.00% w/w, were synthesized through a simple sol-gel method. Fourier-transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), Ultraviolet-Visible (UV-Vis) spectroscopy, nitrogen adsorption−desorption isotherms, X-ray photoelectron spectroscopy (XPS), and X-ray absorption near-edge structure spectroscopy (XANES) were used to characterize the synthesized nanoparticles. The characterization of the Fe-doped TiO(2) nanoparticles revealed the predominant presence of anatase crystalline form, as well as the incorporation of the Fe(3+) ions into the crystal lattice of TiO(2). The photocatalytic assessment of the Fe-doped TiO(2) nanoparticles indicated that the low iron doping titania (0.05 and 0.10% w/w) have a positive effect on the photocatalytic degradation of Methyl Orange under visible radiation. Moreover, FTIR monitoring of calcium hydroxide pastes enriched with low Fe-doped TiO(2) revealed enhancement of carbonation at both early and later stages. Improved photocatalytic performance and increased lime carbonation, observed in lime coatings with low Fe-doped TiO(2) admixtures, established them as invaluable contributors to the protection of the built environment.