Ultrafast Adsorption of Strontium over β-Alanine-Coordinated 2D Derivatives of Amorphous ZIF-67

⁹⁰Sr, as a hazardous radionuclide to the environment and human health, is a challenge to develop materials with high adsorption capacity and selectivity for its elimination from nuclear wastewater. In this study, 2D amorphous ZIF-67 is synthesized via triethanolamine-mediated morphological modification, followed by tannic acid-directed etching to obtain a 2D derivative of ZIF-67 and sufficiently expose the active sites. Subsequent functionalization with β-alanine yields an easily synthesized and high-efficiency Sr²⁺ adsorbent (2D amorphous TZIF-67-β). Compared with conventional ZIF-67, the 2D amorphous ZIF-67 has higher structural stability and more active sites and can load more β-alanine to enhance its adsorption capacity for Sr²⁺. Especially, 2D amorphous TZIF-67-β achieves over 90% Sr²⁺ removal efficiency within 10 min under strongly alkaline conditions (pH 12), addressing the scarcity of adsorbents operable in such environments. The adsorption process is well-fitted by the pseudo-second-order kinetic model and Langmuir adsorption isotherm, with a maximum capacity of 175.87 mg·g⁻¹. Simulated real water contamination scenarios further reveal that 2D amorphous TZIF-67-β maintained high Sr²⁺ removal efficiency, demonstrating practical application potential.