Preparation and photocatalytic activity of magneticTiO₂-Fe₃O₄/MIL-101(Cr) composites

The magnetic TiO₂-Fe₃O₄/MIL(Material Institute Lavoisier)-101(Cr) composites were synthesized via in situ hydrothermal method. The structure and performance of composites were characterized by XRD, SEM, UV-Vis DRS, BET and superconducting magnet system. The photocatalytic activity of TiO₂-Fe₃O₄/MIL-101(Cr) composites were investigated by photocatalytic degradation of MB solution, and the stability of TiO₂-Fe₃O₄/MIL-101(Cr) composites was also studied. The results show that the thiohydroxy-modified-Fe₃O₄ and thiohydroxy-modified-TiO₂, can be successfully combined with MIL-101(Cr), and a notable absorption extension in the visible-light region can be observed for the TiO₂-Fe₃O₄/MIL-101(Cr) composites. The TiO₂-Fe₃O₄/MIL-101(Cr)(400) composite exhibits the highest photocatalytic activity, while the corresponding photodegradation efficiency for MB is 80% after 120 min irradiation. The TiO₂-Fe₃O₄/MIL-101(Cr) composites also have a good stability and can be easily separated from solution by an external magnet.