Lanthanide Selective Biomimetic Nanopores

Lanthanides serve as essential elements for modern technology, playing critical roles in batteries, wind turbines, portable electronics, and energy efficient lighting. However, purifying lanthanides from ores and recycling them from end-of-life consumer materials is costly and damaging to the environment due to inefficient separation technologies. Lanthanide-lanthanide ion separations are challenging due to similarity in their hydrated size, with commonly used methods limited to single stage selectivities of ~ 2-3. Here we present supramolecular membrane channel nanopores based on a pillar[5]arene scaffold with appended diphenylphosphine oxide (DPP) ligands that show high transport selectivity (~18:1) of the medium lanthanide, Europium (Eu3+), over all measured monovalent and divalent ions, including protons. These membrane channels also have high lanthanide-lanthanide transport selectivity with Eu3+/La3+ selectivity of >40 and Eu3+/Yb3+ selectivity of ~30. Molecular dynamics simulations indicate that the high selectivity observed is due to specific water-mediated interactions between the hydrated ions and the channel. Our findings could offer a promising avenue for efficient lanthanide separations, marking an important advancement towards a greener and more sustainable future.