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.