Degradation of Methyl Orange in Aqueous Solution via Magnetic TiO 2 /Fe 3 O 4 Conjugated with Persulfate

The magnetic nanocomposite TiO 2 /Fe 3 O 4 coupled with persulfate (PS) under UV irradiation for methyl orange (MO) degradation in aqueous solution was investigated in this study. The features of TiO 2 /Fe 3 O 4 were characterized via SEM, XPS, UV–Vis, and MPMS. The effect of several operating parameters including PS concentration, TiO 2 /Fe 3 O 4 dosage, MO concentration, and pH was assessed in UV/TiO 2 /Fe 3 O 4 /PS system. The removal of MO via UV/TiO 2 /Fe 3 O 4 /PS reached 99.5% under the following conditions: [PS] = 60 mM; [TiO 2 /Fe 3 O 4 ] = 0.4 g/L; [MO] = 20 mg/L; pH = 3.0; T = 25 ℃; UV = 300 W; and t = 150 min. In addition, possible mechanisms of TiO 2 /Fe 3 O 4 photocatalysis, PS activation, and MO degradation were analyzed. Moreover, TiO 2 /Fe 3 O 4 was easily separated from the reacted solution by magnets and had relatively stable recycling performance. Overall, the application of UV/TiO 2 /Fe 3 O 4 /PS can be introduced as an effective method for MO and even dyes removal.