Magnetic and high rate adsorption properties of porous Mn1−xZnxFe2O4 (0 ⩽ x ⩽ 0.8) adsorbents

Porous spinel ferrites Mn1−xZnxFe2O4 (0 ⩽ x ⩽ 0.8) are synthesized by a simple sol–gel method with egg white. All samples exhibit porous morphologies and large BET surface area (SBET). The substitution of Zn2+ affects the magnetic properties of ferrites and the adsorption properties of methylene blue (MB) on ferrites, obviously. The saturation magnetization (Ms) of Mn1−xZnxFe2O4 increases before x = 0.4, and decreases with further increase of Zn2+ substitution. This can be ascribed to the changes of the cationic distribution and the variation of spin arrangement in A-site and B-site of spinel structure. All samples show high adsorption capacity and the removal efficiencies of MB reach up to >90% within 3 h. The Zn2+ substitution accelerates the adsorption rate and capacity of MB on Mn1−xZnxFe2O4. The quickest adsorption occurred at x = 0.2 and the largest adsorption capacity occurred at x = 0.8.

Porous ferrites Mn1−xZnxFe2O4 (0 ⩽ x ⩽ 0.8) show high speed adsorptive properties of methylene blue (MB) and can be separated conveniently by a magnet for their ferromagnetic properties. Figure optionsDownload high-quality image (107 K)Download as PowerPoint slideResearch highlights
► All samples of Mn1−xZnxFe2O4 synthesized by sol–gel method are porous shapes and Zn2+ addition can affect their morphologies.
► The porous of Zn2+ doped ferrite Mn1−xZnxFe2O4 show both ferromagnetic and adsorption properties, which realize the effective adsorption and convenient magnetic separation.
► Moreover, the addition of Zn2+ accelerate the adsorptive speed obviously, the quickest adsorption.