Magnetic, structural and adsorption properties for methylene blue of PAA/MnFe2O4 nanocomposite

PAA/MnFe$_{\mathrm{2}}$O$_{\mathrm{4}}$ nanocomposite was fabricated by a hydrothermal procedure and ultrasonic wave-assisted method. The morphology of the synthesized MnFe$_{\mathrm{2}}$O$_{\mathrm{4}}$ ferrite nanocrystals is the exclusive octahedral structure. The saturation magnetization Ms of as-synthesized nanoparticles reached 74.6emu/g. FTIR spectrum confirms the coating of PAA on the surface of MnFe$_{\mathrm{2}}$O$_{\mathrm{4}}$ ferrite nanoparticles. Here, the PAA coating does not lead to a deterioration in magnetic performance. Moreover, the PAA/MnFe$_{\mathrm{2}}$O$_{\mathrm{4}}$ nanocomposites were applied to remove Methylene Blue (MB) from wastewater. Compared with the nanoparticles without coating, the PAA coating significantly enhanced the adsorption capacity of MB onto MnFe$_{\mathrm{2}}$O$_{\mathrm{4}}$ magnetic nanoparticles, where a rapid and efficient removal of MB was observed. The research suggests that as-synthesized PAA/ MnFe$_{\mathrm{2}}$O$_{\mathrm{4}}$ nanocomposites have promising and potential applications in water treatment for removal of dyes.