Facile preparation of magnetic mesoporous Fe3O4/C/Cu composites as high performance Fenton-like catalysts

Abstract Fe-Cu composites with different compositions and morphologies were synthesized by a hydrothermal method combined with precursor thermal transformation. γ-Fe 2 O 3 /CuO and α-Fe 2 O 3 /CuO were obtained by calcining the Fe and Cu tartrates under air atmosphere at 350 °C and 500 °C, respectively, while Fe 3 O 4 /C/Cu was obtained by calcining the tartrate precursor under N 2 atmosphere at 500 °C. The Fe 3 O 4 /C/Cu composite possessed mesoporous structure and large surface area up to 133 m 2  g −1 . The Fenton catalytic performance of Fe 3 O 4 /C/Cu composite was closely related to the Fe/Cu molar ratio, and only proper amounts of Fe and Cu exhibited a synergistic enhancement in Fenton catalytic activity. Cu inclusion reduced Fe 3+ to Fe 2+ , which accelerated the Fe 3+ /Fe 2+ cycles and favored H 2 O 2 decomposition to produce more hydroxyl radicals for methylene blue (MB) oxidation. Due to the photo-reduction of Fe 3+ and Cu 2+ , the Fenton catalytic performance was greatly improved when amending with visible light irradiation in the Fe 3 O 4 /C/Cu-H 2 O 2 system, and MB (100 mg L −1 ) was nearly removed within 60 min. The Fe 3 O 4 /C/Cu composite showed good recyclability and could be conveniently separated by an applied magnetic field. Compared with conventional methods for mesoporous composite construction, the thermolysis method using mixed metal tartrates as precursors has the advantages of easy preparation and low cost. This strategy provides a facile, cheap and green method for the synthesis of mesoporous composites as excellent Fenton-like catalysts, without any additional reductants or organic surfactants.