Oxygen hyper stoichiometric trimetallic titanium doped magnesium ferrite: Structural and photocatalytic studies

Oxygen hyper stoichiometric titanium doped magnesium ferrite, Mg1-xTixFe2O4+δ (x = 0–1.0) nanoparticles (NPs) were synthesized using sol-gel method. XRD analysis revealed a decrease in the lattice parameter from 8.9 to 8.3 Å and confirmed the incorporation of Ti4+, a smaller ionic radius dopant. Presence of M-O vibrational bands at tetrahedral and octahedral sites were authenticated by FT-IR analysis. The observed reduction in saturation magnetization values from 23.3 emug−1 to 18.3 emug−1 was ascribed to the doping of non-magnetic Ti4+ ions in MgFe2O4 NPs. BET studies corroborated the mesoporous nature of the NPs and doped ferrite NPs displayed larger surface area (53.0–73.0 m2g-1) as compared to pristine ferrite NPs (32.8–39.0 m2g-1). Optical studies displayed red shift in the absorption edge of the Ti4+ doped MgFe2O4 NPs in contrast to pristine NPs. Oxygen hyper stoichiometry in the doped ferrite NPs was determined experimentally. Photoluminescence emission spectra exhibited reduction in the emission intensity in case of Ti4+ doped NPs which supported their higher light capturing potential. Among synthesized doped ferrite NPs Mg0.5Ti0.5Fe2O4.5 NPs exhibited maximum (98%) photodegradation capacity for rhodamine B. The •O2− and •OH were the main reactive species in the photodegradation. The present studies have clearly shown the potential of tuning the composition of oxygen hyper stoichiometric ferrite Mg0.5Ti0.5Fe2O4.5 for the removal of toxic organic contaminants from water.