Constructed a stable coordination polymer for highly efficient and selective capture of thorium

The efficient separation of thorium (Th) from chemically similar rare earth elements (REEs) is technically challenging. In this work, a stable coordination polymer (Ni-tfc-CP) was fabricated by adopting the strategy of in-situ incorporation of hydrophobic groups. Ni-tfc-CP exhibits excellent structural stability over a wide pH range of 2–11 and under high-temperature conditions up to 247°C. The abundant carboxyl oxygen active binding sites on the surface of Ni-tfc-CP, provides favorable environment for Th(IV) uptake. The maximum adsorption capacity was calculated to 518.9 mg g⁻¹, by fitting the equilibrium data to the Langmuir model. Moreover, it showed an ultra-fast adsorption rate and reached equilibrium within 5 minutes. Notably, competitive tests confirmed the superior selectivity of Ni-tfc-CP for Th(IV), with a high distribution coefficient of 6×10⁵ mL g⁻¹. This study provides meaningful guidance for the rational development of functional materials toward nuclide separation.