Physico-chemical characterization and photocatalytic activity assessment under UV-A and visible-light irradiation of iron-doped TiO2 nanoparticles

Abstract

In this work, undoped TiO2 and Fe-doped TiO2 materials as photocatalysts for water remediation, were synthesized using wet chemical methods (sol-gel + precipitation). Their crystalline structure, optical and morphological properties were explored using X-ray diffraction (XRD), Fourier-transform infrared (FTIR) and Raman spectroscopies, UV-vis diffuse reflectance (DRS) and photoluminescence (PL) spectroscopy, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy coupled to the energy dispersive X-Ray spectroscopy (SEM-EDS). The photocatalytic performance of the synthesized materials was assessed through the degradation of methyl orange (MO) under UV-A and visible-light irradiations. The structural study showed the existence of predominate anatase phase in all synthesized nanomaterials. The optical study showed a widening of the band gap for Fe-doped TiO2 materials and revealed a decrease in charge carrier’s recombination for all Fe-doped TiO2 nanomaterials compared to undoped TiO2. The morphological study confirmed the nanometric scale of the materials particles. The photocatalytic experiments revealed an enhanced photocatalytic activity of 0.5%wt Fe-doped TiO2, only under UV-A light, compared to the rest of the prepared nanomaterials. The enhanced photocatalytic activity has been attributed to the efficient charge separation of electrons and holes.