Enhanced Separation of Potassium Ions by Spontaneous K-Induced Self-Assembly of a Novel Metal-Organic Framework and Excess Specific Cation-π Interactions

摘要

A novel metal-organic framework (MOF) was fabricated by spontaneous K~+-induced supramolecular self-assembly with the embedded tripodal ligand units. When the 3D ligand was loaded onto Fe3O4@mSiO2 core-shell nano-particles, it could effectively separate K~+ ions from a mixture of Na~+, K~+, Mg~(2+), and Ca~(2+) ions through nanoparticle-assisted MOF crystallization into a Fe3O4@mSiO2@MOF hybrid material. Excess potassium ions could be extracted because of the specific cation-n interaction between K~+ and the aromatic cavity of the MOF, leading to enhanced separation efficiency and suggesting a new application for MOFs.