Synthesis of mesoporous magnetic MnFe2O4@CS-SiO2 microsphere and its adsorption performance of Zn2+ and MB studies

Because of its superior physical and chemical properties, MnFe2O4 is regarded as one of the best magnetic material alternatives for Fe3O4. However, MnFe2O4 alone cannot remove heavy metal ions and dyes. Here, we report on a new mesoporous magnetic MnFe2O4@CS-SiO2 microsphere material that was synthesised via the hydrothermal method to remove Zn2+ and methylene blue (MB) in simulated textile wastewater. The composite was characterised using a vibrating sample magnetometer, scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy, X-ray powder diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and a Brunauer-Emmett Teller analysis. The pH, adsorbent dosage, initial adsorbate concentration, and reaction time effects on the removal of Zn2+ and MB were studied under different conditions, and a possible removal mechanism was proposed and discussed. The experimental results show that the suitable pH range for MB adsorption was extremely wide, and the adsorption equilibrium can be reached within 30 min. In addition, the prepared material has excellent stability. With an excellent removal efficiency as high as 56.1% and 93.86% for Zn2+ and MB, respectively, after five consecutive cycles and a superior adsorption capacity compared with other materials, the prepared composite in this paper proved to be a promising and effective magnetic adsorbent for the removal of Zn2+ and MB from textile wastewater.