Hydrothermal synthesis and photo-Fenton degradation of magnetic MnFe 2 O 4 /rGO nanocomposites

Magnetic recoverable MnFe 2 O 4 /rGO nanocomposites were synthesized via a facile one-pot hydrothermal method. The microstructure, morphology, optical and magnetic property were characterized by X-ray diffraction, high-resolution transmission electron microscope, ultraviolet–visible spectroscopy, N 2 adsorption–desorption technique, photoluminescence spectroscopy and vibrating sample magnetometer. The photo-Fenton degradation activity of the MnFe 2 O 4 /rGO composites was investigated using the methylene blue (MB) in aqueous solution under the simulated sunlight. The results show that MnFe 2 O 4 nanoparticles with cubic spinel structure were loaded on the surface of rGO, possessing irregular ellipsoid with uniform particle size and good dispersion. The band gap of MnFe 2 O 4 /rGO is narrower than that of pure MnFe 2 O 4 and exhibits redshift. The weak luminescence of MnFe 2 O 4 /rGO nanocomposites indicates the efficient separation of photoexcited electron/hole pairs. MnFe 2 O 4 /rGO nanocomposites display superior photo-Fenton degradation efficiency of MB, exhibit obvious room temperature ferromagnetism and can be readily recovered by external magnetic field. MnFe 2 O 4 /rGO nanocomposites exhibit the best degradation efficiency under the condition of pH 9, 0.5 mL H 2 O 2 and 0.06 g mass fraction in photo-Fenton degradation of MB dye. The radical scavenger tests demonstrate that ·OH, e − and h + are the main active species and play a decisive role, and rGO plays a vital role in synergistic enhancement of photo-Fenton degradation.