Facile synthesis of Fe3O4/MIL-101 nanocomposite as an efficient heterogeneous catalyst for degradation of pollutants in Fenton-like system

An active Fe3O4/MIL-101 hybrid material was prepared via a simple in situ solvothermal method and characterized as a heterogeneous Fenton-like catalyst for Rhodamine B (RhB) degradation. The Fe3O4/MIL-101 exhibited enhanced catalytic performance for RhB degradation in a neutral solution. Under optimized conditions, almost 100% removal of 10 mg L-1 RhB was achieved in 30 min using 0.5 g L-1 Fe3O4/MIL-101 and 20 mM H2O2 at initial pH 7. The reusability of Fe3O4/MIL-101 was also investigated after four runs. On the basis of the characterization of the catalyst, the results of metal leaching, the effects of radical scavengers, and hydroxyl radical (OH) determination, it was concluded that RhB is decomposed mainly by the attack of the hydroxyl radical (OH), generated by the reaction of Fe2+ species with H2O2. MIL-101 showed a significant synergistic effect with Fe3O4, in which it played the role of a solid-acid catalyst with Lewis acid sites on its surface, ensuring that a Fenton-like reaction occurred in the neutral solution.