TiO 2 Nanoparticles with Mixed Anatase-Rutile Phase Structure Doped with Different Concentrations of Iron for Photocatalytic Activity in Degrading Methylene Blue

Methylene blue as dye waste test was used to facilitate the photodegradation of iron-doped anatase-rutile mixed phase TiO2 nanoparticles (NPs) under visible light, which were synthesized using the co-precipitation method. These nanoparticles were characterized using X-Ray diffraction (XRD), UV-Vis, FTIR, field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), and energy-dispersive X-Ray spectroscopy (EDX). The XRD analysis revealed that the diffraction patterns exhibited two-phase structures, namely anatase and rutile phase structures, where the intensity of the rutile phase structures was greater than that of the anatase phase structures. The Ultraviolet-Visible Spectroscopy (UV-Vis) measurements indicated that there is a reduction of the bandgap energy of the Fe-TiO2 NPs. FESEM micrographs revealed that agglomerations formed clusters, and SEM results showed that the nanoparticles aggregate to create structures on the surface that resemble edelweiss flowers. Based on Kramers-Kronig analysis, the reduction in optical phonon (Δ(𝐿𝑂−𝑇𝑂)) cm-1 difference with a decrease in the rutile fraction as a function of Fe increased. The reduction in the rutile phase fraction correlated with a decrease in photocatalytic activity, indicating that the rutile phase has a crucial role in the photodegradation process (1wt% achieve 𝑘ads rate: 0.00273 min-1). These results suggest that iron-doped anatase-rutile mixed-phase TiO2 nanoparticles are suitable as photocatalysts.