Magnetic properties and photocatalytic activity of Bi1-xSmxFe1-yNiyO3 nanoparticles for methyl red degradation

In this work, Bi1−xSmxFeO3 (x = 0.1, 0.08, 0.06, 0.04, 0.02) and Bi0.094 Sm0.06 Fe1−y NiyO3 nanoparticles (y = 0.05, 0.03, 0.01) were synthesized by sol–gel method. The structural, microstructural, magnetic, and optical properties of Bi1−xSmxFe1−yNiyO3 nanoparticles were characterized by using X-ray diffraction, field-emission scanning electron microscopy, the energy-dispersive X-ray analysis, vibrating sample magnetometry and UV–Vis reflectance spectra at room temperature. The structural investigations indicate that the unit cell volume decreases with Sm ion doping, while it increases with substituting Ni ions in the Bi1−xSmxFe1−yNiyO3 nanoparticles. Moreover, the magnetic properties were enhanced by doping Sm and Ni ions. The photocatalytic activities of Bi1−xSmxFe1−yNiyO3 nanoparticles were investigated to degrade methyl red (M.R.) in an aqueous solution. For this purpose, the M.R. degradation with the synthesized photocatalysis was evaluated at room temperature under dark and visible light exposure using a mercury lamp (150 W). The results indicated that the highest photodegradation of M.R. is obtained using Bi0.94Sm0.06Ni0.03Fe0.97 nanoparticles as a photocatalyst in the presence of hydrogen peroxide in an acidic media (pH 3). Besides, the photocatalytic activity of Bi1-xSmxFe1-yNiyO3 (x = 0.06, and y = 0.01, 0.03, 0.05) is higher than that of Bi1−xSmxFeO3 (x = 0.0, 0.02, 0.04, 0.06, 0.08) nanoparticles for the photodegradation of MR. Besides, the Sm and Ni co-doped BFO nanoparticles have a greater magnetic property than the Sm-doped BFO nanoparticles, leading to a simple and fast separation of catalyst using a strong magnet after the M.R. degradation. Under the optimum conditions, the M.R. degradation efficiencies under visible-light illumination for 60 and 100 min were 97.34 and 85.76% for Bi0.94Sm0.06Ni0.03Fe0.97 and Bi094Sm0.06FeO3 nanoparticles at pH 3.0.