Amorphous ZrP anchored on MOFs derived porous carbon for efficient fluoride removal from water

Fluoride ion contamination in water bodies poses a serious threat to human health, necessitating the urgent development of highly efficient adsorbents to mitigate fluoride pollution in drinking water. This study constructed a novel composite adsorbent material, ZrP@NC-X, by combining amorphous ZrP with porous carbon (NC) derived from calcined and etched ZIF-8. Benefiting from both the enhanced mass transfer and increased active site utilisation provided by NC, alongside the abundant adsorption sites offered by amorphous ZrP, ZrP@NC-3 achieves effective removal of fluoride ions from aqueous solutions. At a dosage of 1 g/L, adsorption equilibrium is reached within 200 min, with a maximum adsorption capacity of 24.08 mg/g. Furthermore, ZrP@NC-3 exhibits outstanding fluoride ion adsorption performance across a broad pH range of 3 to 7, maintaining high selectivity towards fluoride ions even in the presence of PO4 3− ,CO 3 2− ,HCO 3 − and SO 4 2− . Systematic characterisation and mechanistic analysis indicate that fluoride adsorption is primarily driven by electrostatic interactions with the ZrP@NC-3 surface and ligand exchange with hydroxyl groups on the ZrP surface. Consequently, the developed ZrP@NC-X material holds promise as an ideal candidate for highly efficient fluoride removal.