(Y3+/Sm3+)-doped and co-doped CoFe2O4 for heterogeneous advanced oxidation process: structural, magneto-optical, and photocatalytic investigations.

The photocatalytic properties of CoFe₂O₄ nanoparticles were activated by the doping and co-doping of a low level of Y³⁺ and Sm³⁺ cations. After optimizing the annealing temperature, 900 °C was found to be the optimal temperature for the successful incorporation of Y³⁺ and Sm³⁺ into the spinel structure. The purity of our samples annealed at 900 °C was confirmed using several characterization methods, including PXRD, SEM, XPS, VSM, FTIR, and Raman spectroscopy. Thus, we were able to increase the photocatalytic degradation of orange G dye from 9.9 to 64.63% for the Sm³⁺-doped sample, 76.42% for the Y³⁺-doped sample, and even 85.81% for the co-doped sample under 60 min of UV–visible light irradiation. The beneficial effect of samarium and yttrium doping and co-doping is attributed to several factors: the first factor is doped and co-doped rare earth impurities induce distortion in the lattice, the larger the ionic radii of dopant element, the highest is the photocatalytic activity; second factor, upon doping and co-doping of rare earth impurities in the structure of CoFe₂O₄ leads to the creation of donor state level within the band gap, causing the Fermi energy to shift near the conduction band. Third factor, co-doping produced strong interactions, which accelerated photocarrier mobility and transport; lastly, longer electron-holes lifetime. We have provided a detailed study of the structural, vibrational, and optical properties to support our conclusions. [ABSTRACT FROM AUTHOR]