Efficient Capture of Sr2+ from Acidic Aqueous Solution by an 18-Crown-6-Ether based Metal Organic Framework

The capture of highly radiotoxic Sr-90 from an acidic waste solution during used fuel reprocessing and environmental remediation in a nuclear accident is desirable and challenging. Herein, we show a metal organic framework material (SNU-200) functionalized with an 18-crown-6-ether, whose specific binding site with an excellent affinity toward strontium leads to excellent Sr2+ adsorption capability under acidic conditions. This material exhibits a high adsorption capacity (44.37 mg g(-1) at pH = 3), remarkable affinity (K-d = 3.63 x 10(4) mL g(-1)) and ultrahigh selectivity in the presence of interfering coexisting ions such as Na+, K+, Cs+, Mg2+, and Ca2+.