CoFe2O4−Fe3O4Magnetic Nanocomposites as Photocatalyst for the Degradation of Methyl Orange Dye

Abstract

We report the investigation of temperature-dependent magnetic properties and photocatalytic activity ofCoFe2O4−Fe3O4magnetic nanocomposites (MNCs) synthesized by hydrothermal process. Room-temperature magnetic hysteresis (M-H) loops result enhanced saturation magnetization of 90 emu/g and coercivity (HC) of 530 Oe forCoFe2O4−Fe3O4MNCs. With decreasing temperature to 20 K,HCincreases from 500 Oe to 6800 Oe, and the M-H loops exhibit exchange coupling feature betweenCoFe2O4andFe3O4. Low- and high-temperature-dependent magnetization measurements confirm that the blocking temperature lies above 300 K and the presence of two magnetic phase transitions corresponding toCoFe2O4andFe3O4, respectively. The photocatalytic activity of the MNCs has been examined on the reduction of methyl orange (MO), a colored compound used in dyeing and printing textiles. The observed results suggest that theCoFe2O4−Fe3O4MNCs act as an excellent photocatalyst on the degradation of organic contaminants and degrade 93% of MO in 5 hours of UV irradiation. The photocatalytic activity of MNCs is attributed to remarkably high band gap energy and small particle size. Also, the MNCs with a reproducible photocatalytic activity are well separable from water media by applying external magnetic field and acts as a promising catalyst for the remediation of textile wastewater.