Anthracene-Functionalized Terbium-Organic Framework for Luminescent Sensing and Adsorptive Removal of Aqueous Pollutants

The detection and removal of heavy metal ions and organic dyes in wastewater are crucial yet highly challenging. Herein, we report a stable terbium-based metal-organic framework, LCUH-125, assembled from Tb³⁺ ions and an anthracene-containing aromatic carboxylic acid ligand. LCUH-125 features a two-dimensional layered structure further extended into a three-dimensional supramolecular network through anthracene π···π stacking, with an interlayer spacing of 6.0-6.34 Å. This structure provides abundant π···π and C-H···π interactions, enabling efficient adsorption of methylene blue (MB, 528.1 mg·g⁻¹) and rhodamine B (RhB, 147.8 mg·g⁻¹) and selective separation of MB/methyl orange and RhB/methyl orange mixtures. Benefiting from excellent luminescence and water stability, LCUH-125 serves as a highly selective and sensitive multiresponsive luminescent sensor for Fe³⁺, Cr³⁺, Al³⁺, and Cr₂O₇²⁻ in aqueous solution with high Stern-Volmer constants. The adsorption and sensing mechanisms were systematically elucidated by characterizations and theoretical calculations. This work offers a valuable strategy for designing dual-functional MOF materials for wastewater treatment and luminescent sensing.