Abstract
Green and sustainable (90)Sr uptake is urgently needed for radionuclides remediation. Herein, we propose an efficient strategy based on electrochemically switched ion exchange (ESIX) method to enhance (90)Sr uptake using electroactive ion exchange material. A titanate perovskite (Na(2)La(2)Ti(3)O(10)) with outstanding acid, irradiation resistance, and thermal stability can effectively capture Sr(2+) and achieve remediation of actual acidic (90)Sr-containing liquid waste (R(Sr) > 99%). Na(2)La(2)Ti(3)O(10) is prepared as working electrode C@NaLaTiO to enhance Sr(2+) uptake via ESIX. Remarkably, the Sr(2+) adsorption capacity increases (from 104.84 to 175.43 mg·g(-1)) and high selectivity for Sr(2+) is maintained even under strongly acidic solutions. The Sr(2+) adsorption-desorption can be controlled via facile potential modulation. Mechanism study indicates that efficient Sr(2+) capture originates from the ion exchange between Sr(2+) and interlayer Na(+) in Na(2)La(2)Ti(3)O(10) coupled with the electrochemical redox reaction between Ti(4+)/Ti(3+) and the increase in oxygen vacancy. Density functional theory calculations support that ESIX enhances Sr(2+) adsorption by increasing the binding energy of anionic [La(2)Ti(3)O(10)](n)(2n-) layers towards Sr(2+). This study offers a convenient and environmentally friendly way for the efficient (90)Sr enrichment from radioactive waste liquids.