The Effect of Iron on TiO₂ Nanostructures Deposited on Porous Platforms for Water Purification ^†

In this study, polyethylene-glycol-modified titanium dioxide (TiO₂) nanopowders were prepared using a solvothermal method under microwave irradiation with further impregnation on water filters by drop-casting. The effect of adding iron with different molar ratios (1, 2 and 5%) was studied. The characterization of the synthesized nanomaterials was performed by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), X-Ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The optical characterization of the materials was also carried out. SEM showed that pure TiO₂ and Fe-TiO₂ nanostructures presented similar nanosized and spherical particles that uniformly covered the substrates. From XRD, the presence of anatase TiO₂ phase in all nanopowders was confirmed. XPS and UV–VIS absorption spectroscopy emission spectra revealed the presence of Fe ions on the Fe-TiO₂ nanostructures that led to the introduction of new intermediate energy levels, which probably contributed to the enhancement of photocatalytic activity. The photocatalytic results under solar irradiation demonstrated increased photocatalytic activity in the presence of the 5% Fe-TiO₂ nanostructures (Rhodamine B degradation of 85% after 3.5 h). This work presents novel functionalized photocatalytic nanoplatforms, which were revealed to be promising for decomposing organic dyes from wastewater.