The effect of phosphonates on lanthanide separation for surface-grafted porous zirconia

: Otaki Miho; Suominen Topi; Suorsa Valtteri; Hietala Sami; Koivula Risto T.

Publisher: Royal Society of Chemistry (RSC)

: 2023

: Materials Advances

: 4

: 2

: 551-560

: 560

: 2633-5409

DOI: https://doi.org/10.1039/d2ma00928e

: https://doi.org/10.1039/d2ma00928e

The effect of phosphonate groups on selective lanthanide sorption for a series of inorganic-organic hybrid materials was investigated. Four functional ligands with an increasing number of aminomethylenephosphonate groups were attached to the porous zirconia matrix via the post-synthetic grafting method. Successful surface grafting was confirmed by FTIR and P-31 MAS-NMR spectroscopies. All the synthesized hybrids showed a lanthanide uptake of about 100 mu mol g(-1) at pH 3. The sorption studies revealed that the hybrids of ligands with a larger number of phosphonate groups possess higher selectivity, as one with the largest number showed a separation factor of over 80 for La3+ and Lu3+. Fixed-bed column experiments also demonstrated the materials' favored uptake of Lu3+ over La3+ at pH 3, in addition to the reusability and applicability to the actual separation settings. These results propose strategies for the selection of organic ligands for hybrid sorbent synthesis.