Enhancing radiostrontium uptake by a layered titanate perovskite via sustainable electrochemically switched ion exchange

Green and sustainable 90Sr uptake is urgently needed for radionuclides remediation. Herein, we propose an efficient strategy based on electrochemically switched ion exchange (ESIX) method to enhance 90Sr uptake using electroactive ion exchange material. A titanate perovskite (Na2La2Ti3O10) with outstanding acid, irradiation resistance, and thermal stability can effectively capture Sr2+ and achieve remediation of actual acidic 90Sr-containing liquid waste (RSr > 99%). Na2La2Ti3O10 is prepared as working electrode C@NaLaTiO to enhance Sr2+ uptake via ESIX. Remarkably, the Sr2+ adsorption capacity increases (from 104.84 to 175.43 mg·g−1) and high selectivity for Sr2+ is maintained even under strongly acidic solutions. The Sr2+ adsorption-desorption can be controlled via facile potential modulation. Mechanism study indicates that efficient Sr2+ capture originates from the ion exchange between Sr2+ and interlayer Na+ in Na2La2Ti3O10 coupled with the electrochemical redox reaction between Ti4+/Ti3+ and the increase in oxygen vacancy. Density functional theory calculations support that ESIX enhances Sr2+ adsorption by increasing the binding energy of anionic [La2Ti3O10]n2n− layers towards Sr2+. This study offers a convenient and environmentally friendly way for the efficient 90Sr enrichment from radioactive waste liquids. Green and sustainable 90Sr uptake is urgently needed for radionuclides remediation. Here the authors propose an efficient strategy based on the electrochemically switched ion exchange (ESIX) method to enhance 90Sr uptake using the electroactive ion exchange material.