Wrinkled Layered Sulfide With Tunable Channels Unlocks Precision in Rare Earth Extraction From Radioactive Wastewater

Abstract Dimensionally adjustable channels are incorporated into a crystalline lattice via strategic stacking of wrinkled layers, boosting rare earth element (REE) ion exchange performance due to the eliminated energy‐intensive dehydration and channel rigidity. In [(CH 3 ) 2 NH 2 ] 2 Ga 2 Sb 2 S 7 ( GaSbS‐1 ), the lone electron pair (LEP) on Sb 3+ in the trigonal pyramidal {SbS 3 } influences Ga─S bond orientations, creating wrinkled [Ga 2 Sb 2 S 7 ] n 2 n − layers. Staggered stacking forms parallel channels occupied by [(CH 3 ) 2 NH 2 ] + cations, facilitating outstanding exchange for REE 3+ ions (Y 3+ , La 3+ −Lu 3+ ). Dynamic interlamellar expansion endows GaSbS‐1 with remarkable kinetics ( R = 97.14%–99.40% within 5 min; k 2 = 2.592–3.462 g mg −1 min −1 ) and capacities (63, 125, 143, and 138 mg g −1 ) for Y 3+ , Ce 3+ , Eu 3+ , and Tm 3+ . It exhibits structural stability across pH = 2–12, with K d values > 10 4 –10 5 mL g −1 at pH = 4–9, and superior selectivity for REE 3+ over competing ions. Performance remains robust in real aqueous environments, including sea water, with maximum REE 3+ removal rates >90%. Rapid kinetics enable efficient column filtration ( R = 93.10%–98.51%) and recycling capability. The GaSbS‐1 /PTFE membrane achieves 99.71%–99.95% removal of trace REE 3+ at 1.38 mL min ‒1 cm ‒2 (0.17 s contact time). With high yield, irradiation resistance, and facile elution, GaSbS‐1 is a proof‐of‐concept exchanger for purifying REE‐contaminated radioactive wastewater.