Structural, optical, physio-chemical properties and photodegradation study of methylene blue using pure and iron-doped anatase titania nanoparticles under solar-light irradiation

Pure and iron-doped titania nanoparticles have been successfully synthesized using inorganic salt titanium oxysulfate and ferrous sulfate. The nanoparticles are characterized by XRD, Raman, BET, UV/Vis/DRS, PL, HRTEM/EDAX, and XPS techniques. Formation of pure anatase framework is confirmed from the XRD and Raman analysis. The study shows decrease in crystallite size with the increase in iron concentration. N₂ adsorption–desorption isotherms reveals an increase in specific surface area with iron concentration. Elemental analysis of selective nanoparticles confirms the presence of iron. Moreover, HRTEM micrographs show that, the particles are in nano-meter range. Red shifts are found in the absorption edge due to iron doping in titania nanoparticles. Presence of Fe³⁺ in the anatase lattice framework is observed from the XPS analysis. Pure titania nanoparticles have showed better performance for photocatalytic degradation of methylene blue. Addition of H₂O₂ with iron-doped titania nanoparticles results in improved rate of photodegradation compared to pure titania nanoparticles (about 16-fold using 10 wt% iron doped titania and only fivefold using pure titania).