Photocatalytic Removal of Methylene Blue Dye Using CoZnFe₂O₄/SiO₂ Magnetic Nanoparticles

Abstract

The magnetic photocatalyst of CoZnFe2O4/SiO2 nanoparticles has been synthesised to degrade methylene blue (MB) dye. The CoZnFe2O4 nanoparticles were prepared by co-precipitation method under mechanical stirring and coated with SiO2 by stöber method using Na2SiO2 with various concentrations of 5%, 10%, 15%, 20%, 30%, and 50%. The properties of CoZnFe2O4/SiO2 was confirmed by x-ray diffraction (XRD), Fourier transforms infrared (FTIR), vibrating sample magnetometer (VSM), and UV-Visible spectroscopy. XRD analysis revealed that CoZnFe2O4 had the spinel ferrite phase structure with crystalite size of 17.0 nm, and then after coating with SiO2, the size became 17.1 nm. FTIR clearly show an M-O octahedral vibrational bond found with a wavelength of 378 cm-1, O-Si-O, Si-OH, and Si-O-Fe at 1087, 794, and 570 cm-1, respectively. The saturation magnetization (Ms) and coercivity of CoZnFe2O4/SiO2 was 29.0 emu/g and 251.9 Oe, respectively. Furthermore, the results of UV-Visible data presented that the absorption edges CoZnFe2O4/SiO2 in the range of 190 - 600 nm. The percentage of CoZnFe2O4 degradation is 88.4%, while after coted SiO2 50%, the degradation becomes 98.9%.