Fabrication of MgFe2O4-ZnO heterojunction photocatalysts for application of organic pollutants

Novel heterojunction MgFe2O4-ZnO was employed as a photocatalyst to photodegrade organic pollutants Rhodamine B (RhB). This heterojunction was prepared by two steps. First, ZnO flower-like nanotube bundles were synthesized by using a simple solution method at low temperature. Second, MgFe2O4 was coated on ZnO surfaces on the basis of a chemical co-precipitation method. The as-prepared samples were characterized with X-ray diffraction (XRD), UV-3150 double-beam spectrophotometer, field-emission scanning electron microscope (FE-SEM), transmission electron microscopy (TEM), and high-resolution transmission (HRTEM). Photodegradation experiments results indicated that the obtained heterojunction MgFe2O4-ZnO exhibited higher photocatalytic activity than that of pure ZnO or MgFe2O4. Furthermore, MgFe2O4-ZnO could be separated conveniently by using an external magnetic field. The enhanced photocatalytic ability of MgFe2O4-ZnO composites could be attributed to the interconnected heterojunction of MgFe2O4 and ZnO nanoparticles.