摘要
TA@ZIF-8 was synthesized via impregnation for selective Rb + /Cs + recovery from salt-lake brine. • Optimal TA loading (5 g L −1 ) maximizes active sites while preventing self-aggregation. • Rapid kinetics (30 min) and high selectivity for Rb + /Cs + in complex brine matrices. • Pseudo-second-order kinetics and Langmuir isotherm indicate ion exchange–driven uptake. • >82% capacity retained after five cycles, demonstrating robust stability and reusability. Driven by the demand for rubidium (Rb) and cesium (Cs), an adsorption-based strategy employing a tannic acid (TA)-functionalized ZIF-8 composite adsorbent (TA@ZIF-8) was developed for the selective extraction of Rb + and Cs + from salt-lake brine. The incorporation of TA introduced phenolic hydroxyl groups, which significantly enhanced the affinity of ZIF-8 toward alkali metal ions, and enabled efficient adsorption of Rb + and Cs + . The material was systematically characterized by scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM-EDS), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FT-IR). Bath adsorption experiments demonstrated that TA@ZIF-8 achieved maximum capacities of 0.492 mmol g −1 for Rb + and 0.484 mmol g −1 for Cs + within 30 min under alkaline conditions (pH = 11), with high selectivity against competing ions (e.g., Na + , K + ). The adsorption behavior was well described by the pseudo-second-order kinetic model and the Langmuir isotherm model, suggesting a chemisorption-controlled monolayer adsorption process. Furthermore, the adsorbent retained over 80% of its initial adsorption capacity after five adsorption–desorption cycles, demonstrating excellent reusability and structural stability. This work highlights the potential of polyphenol-functionalized metal–organic framework adsorbents for the efficient recovery of alkali metal resources. Download: Download high-res image (354KB) Download: Download full-size image
危险品化学品经营许可证（带存储）