The adsorption of methylene blue (MB) from aqueous solution on a HKUST-1/GO (MOFs : HKUST-1) composite was studied in view of the adsorption isotherm, kinetics and regeneration of the sorbent. The adsorption isotherms of methylene blue (MB) on the HKUST-1/GO composite followed both the Freundlich isotherm and the Langmuir isotherm. Adsorption kinetics and thermodynamic parameters were determined from the experimental data. The used HKUST-1/GO could be regenerated by acetone, so it can be recycled for reuse. The high adsorption capacity and excellent reusability make HKUST-1/GO attractive for the removal of MB from aqueous solution.

A facile preparation of magnetic MOF composites with flexible mercapto group pendants in their pores is realized through solvent-assisted ligand exchange (SALE) under mild conditions in water, and terephthalate in UIO-66 is replaced with mercaptoacetic acid (MAA). After the SALE processing, the crystallinity, porosity, and superparamagnetism of the mercapto functionalized magnetic Zr-MOF (MFC-S) are well maintained, and the obtained MFC-S exhibits a higher adsorption capacity (282 mg g⁻¹) for Hg²⁺ than that of the magnetic Zr-MOF (MFC-O). Furthermore, the prepared MFC-S can be regenerated easily by liquid desorption after adsorption of metal ions and be reused more than 5 times without obvious decrease in removal performance. The proposed SALE method for the preparation of mercapto functionalized magnetic MOF composites (MFCs) is easy-to-operate and low cost, providing not only a reliable porous MFC platform for the removal of metal ions, but also a simple and efficient synthesis route for the preparation of functionalized MFCs which cannot be achieved through conventional approaches.

A magnetic MOF composite with a core–shell nanostructure was prepared and demonstrated to be effective for the removal of Hg²⁺ from water.