• Artemia Cyst-shell in-situ growth of La(OH) 3 nanoparticles for fluoride removal. • the sub-10 nm La(OH) 3 provides ultrahigh capacity (124 mg/g) • three-dimensional macropous structure of matrix provides fast kinetics. • yielding a satisfactory capacity of ∼ 6700 L/kg sorbent for application. The fluoride pollution in water has aroused great concern worldwide, and the fluoride removal by adsorbent is effective technique, and challenges by its weak selectivity and low capacity. Herein, we reported a new insight into the small size of La(OH) 3 nanoparticles preparation and efficient fluoride removal from waters. It relies on the charged amino-acids inside discarded Artemia Cyst-shell, motivated sub-10 nm La(OH) 3 formation (< 10 nm) with high activity, its super-porous (several μm) of three-dimensional skeleton further favors for the fluoride diffusion and kinetics. This hybrid nano-adsorbent exhibits outstanding capacity for defluorination (124 mg/g, 6.53 meq/g), the superior selectivity against various foreign ions, endows a distribution coefficient ( K d ) as high as 1000 mL/g. The super-porous skeleton also brings about rapid kinetic diffusion with ∼ 30 min for equilibrium, yielding a satisfactory capacity of ∼ 6700 L/kg sorbent for the application by the drinking water standards in China. The saturated adsorbent can be readily regenerated and reused without decrease in performance, this technology is promising for mitigating the fluoride contamination problem of worldwide.