Bio inspired core shell architecture with lanthanum driven interlayer regulation for efficient fluoride capture in complex water matrices

Fluoride contamination represents one of the most pervasive and severe challenges in global aquatic environments, creating an imperative for the development of highly efficient F- removal materials. Here, we design a core–shell composite comprising a ZSM-5 molecular-sieve core encapsulated within a lanthanum-intercalated layered double hydroxide (LDH) shell. The ZSM-5 microporous scaffold provides rigid structural support and long-range ion pathways, whereas La3+ doping expands the interlayer spacing and induces wrinkled LDH nanosheets, substantially increasing the surface area and mesoporosity (413 m2·g-1; 0.931 cm3·g-1) and generating highly reactive La–F coordination sites via enhanced M–O polarization. XPS, DFT, and MD results confirm La³⁺ as the strongest Lewis acidic center with the most negative adsorption energy, enabling rapid F- capture and robust interfacial enrichment under NO3- and SO42- backgrounds. Benefiting from the synergistic structural–electronic regulation, Z-NAL4 delivers a Langmuir capacity of 82.4 mg·g-1 at 25 °C and > 99.9% defluoridation at only 0.50–0.60 g·L-1, while retaining 88.1% after five regeneration cycles. Granulated composites further extend the fixed-bed breakthrough time to 13.7 h. This work establishes a unified “structure–electronics–transport” design framework that connects La3+-driven interfacial coordination chemistry with bio-inspired multiscale diffusion, providing a promising platform for treating complex fluoride-laden effluents in fluorochemical production and lithium-salt recovery.