Structural, Optical and Magnetic Properties of Samarium Doped Cobalt Ferrite Nanoparticles for Photocatalytic Applications

Abstract

In the present work, Sm3+ doped spinel cobalt ferrite (CoFe2O4) nanoparticles [CoFe2-xSmxO4 (x = 0.00 to 0.10, with an increment of 0.02)] were fabricated using glycine assisted sol-gel self-ignition method, to understand the effect of Sm3+. The single phase, cubic spinel ferrite phase of the prepared NPs was characterized with the X-ray diffraction (XRD). FTIR spectra confirm the appearance of absorption bands at 554-550 cm–1 and 401-389 cm–1. FE-SEM and HR-TEM observations revealed nearly uniform nanoparticles with slight changes in particle morphology upon Sm3+ incorporation. Elemental diffraction spectra (EDS) show the elements of cobalt (Co), ferric (Fe), samarium (Sm) and oxygen (O) ions with varying intensity. BET analysis demonstrated variation in the specific surface area associated with particle growth. Optical measurements showed a gradual decrease in band gap energy with increasing Sm3+ incorporation. Magnetic measurements confirmed the ferrimagnetic behavior of all samples. The saturation magnetization (Ms) decreased from 77.32 to 60.17 emu g–1, while the coercivity (Hc) increased from 1279.0 to 1752.7 Oe. These changes indicate that Sm3+ substitution influences the magnetic response of CoFe2-xSmxO4 nanoparticles. Sm3+ doping at x = 0.10 improved the photocatalytic efficiency from 86.6% to 88.2%. The changes in structural, optical and magnetic characteristics with Sm3+ substitution were accompanied by improved photocatalytic performance, which support the suitability of CoFe2-xSmxO4 nanoparticles for photocatalytic applications.