Anthracene-Functionalized Two-Dimensional Lanthanide MOFs for Iodine Vapor Capture and Aqueous Dye Adsorption

Efficient adsorbents for organic dyes and iodine capture are critical to mitigate environmental hazards and safeguard public health. Herein, two structurally robust lanthanide MOFs (LCUH-126 and LCUH-127) were solvothermally synthesized with anthracene-based dicarboxylate ligands. Both samples adopt 2D layered structures, which further assemble into 3D supramolecular networks through intermolecular π···π stacking interactions of anthracene moieties, endowing the materials with prominent chemical and thermal stability. The large conjugated π-systems of anthracene together with interlayer -NH- groups endow the two MOFs with excellent adsorption capacity toward organic dyes and iodine. Abundant active sites originating from conjugated skeletons, -NH- moieties and coordinated solvent molecules strengthen the intermolecular interactions between iodine guests and the framework, affording high iodine vapor uptakes of 1.68 and 2.18 g/g at 80 °C. Appropriate interlayer spacing and hydrogen-bonding environments further favor the intercalation of dye molecules and the formation of weak intermolecular interactions. The two MOFs exhibit high adsorption capacities toward methylene blue (MB) and rhodamine B(RhB), and realize selective separation of mixed dye systems driven by electrostatic interaction and size matching. Combined with GCMC simulations, the adsorption mechanisms were elucidated. This work offers a rational strategy and theoretical basis for developing dual-functional adsorbents toward dye and iodine remediation.