Copper(I)/(II)-redox triggered efficient and green rare-earth separation using a heterometallic metal-organic framework

A low-cost, highly efficient and green approach (free of ammonia) to enrich Nd from other rare-earth (RE) elements was reported by using a mixed Cu-RE metal-organic framework whose structure can selectively crystallize heavier RE elements during a one-pot reaction with isonicotnic acid, CuI and mixed RE sources, and release heavier RE elements via oxidation of the cuprous ions under ambient conditions.