Design of a β-cyclodextrin-modified FeOOH/Al(OH)3 hybrid with interfacial activation for synergistic tetracycline enrichment and stabilization

β-CD to Fe-Al oxyhydroxide e − transfer induces positive ESP shift, forming e − -deficient cavity. • Activated β-CD cavity enhances TC affinity, supported by experiments and simplified DFT. • Composite achieves 152 mg/g capacity and good reusability and selectivity. • Cooperative enrichment-stabilization: β-CD recognition & Fe coordination. The development of high-performance adsorbents is often constrained by an inherent trade-off between rapid sequestration kinetics and strong binding capacity. To address this bottleneck, we rationally design a β-cyclodextrin-modified mixed-valent iron (Fe 2+ /Fe 3+ ) ‑aluminum hydroxide hybrid composite (CD-FeAl-HC) for efficient tetracycline (TC) removal. A unique cooperative enrichment-stabilization mechanism is realized in this structured composite: interfacial activated β-CD acts as a molecular recognition unit that rapidly pre-concentrates TC from bulk solution, while the adjacent mixed-valent Fe 2+ /Fe 3+ sites provide strong coordination binding for stable immobilization. DFT calculations further reveal that interfacial electron transfer from β-CD to FeAl-HC induces a distinct positive shift in the electrostatic potential of the β-CD cavity, converting it from an inert pocket into an electron-deficient molecular trap. Benefiting from this synergistic effect, CD-FeAl-HC delivers a competitive maximum adsorption capacity (151.99 mg/g), remarkably fast adsorption kinetics, and excellent anti-interference performance against coexisting ions and natural organic matter. Notably, the composite achieves over 90% removal efficiency for both TC and ofloxacin in mixed solution, while maintaining >90% TC removal in real water matrices (reservoir and landscape water). Furthermore, it retains more than 90% of removal efficiency after 10 consecutive adsorption-desorption cycles, demonstrating outstanding reusability. This work establishes a generalizable design strategy that integrates molecular enrichment and surface stabilization within a single hybrid material, providing a promising framework for the rational construction of high-performance adsorbents toward emerging organic pollutant remediation. Download: Download high-res image (160KB) Download: Download full-size image