Magnetic Fe3O4/ZnCr-layered double hydroxide composite with enhanced adsorption and photocatalytic activity

The novel magnetic Fe3O4/ZnCr-layered double hydroxide (LDH) composite has been successfully fabricated via two-step microwave hydrothermal method. The characterization by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and transmission electron microscope (TEM) reveals the Fe3O4 nanoparticle in size of around 10 nm distributed on the surface of ZnCr-LDH. This provided the magnetic property of the composite, which improved the separation of the composite from aqueous solution. Moreover, the composite adsorbed 528 mg/g of methyl orange (MO) as well as decomposed ∼95% of methylene blue (MB) under UV irradiation. The results reveal a higher removal of dye on the composite, compared to that on ZnCr-LDH under the same conditions. Therefore, our work suggests the novel magnetic Fe3O4/ZnCr-LDH composite to be applicable for organic dyes wastewater treatment.

► The Fe3O4/ZnCr-LDH composite was fabricated via microwave hydrothermal method.
► This composite was more efficient in the removal of dye than ZnCr-LDH.
► This composite adsorbed 528 mg/g of anionic dye.
► It decomposed ∼95% of cationic dye under UV irradiation.
► The magnetic property of this composite made it easily separated from solution.