Inorganic–organic hybrid sorbents were synthesized by grafting porous zirconia with a series of aminomethylenephosphonate ligands. Sorbents with a larger number of phosphonate groups showed higher selectivity for intra-lanthanide separation.

Hydrous ZrO2 materials showed high potential for the selective adsorption of IO3− in the presence of competing anions. The main adsorption mechanism was found to be ion-exchange and efficient regeneration was demonstrated with dilute acid.