Abstract
Efficient and selective removal of 90Sr is an important process for the safe use of nuclear energy. Herein, we investigate and assess the Sr2+ adsorption properties of a metal-organic framework UiO-66-(COOH)2 functionalized by non-bonded carboxylic groups. This MOF is an exciting class of free carboxylic functionalized MOFs that combine chemical stability with gas sorption, dye elimination, and conductivity. Specifically, we show that uniformly distributed carboxyl and water stability make it accessible for loading Sr2+ without structural changes. The FTIR spectroscopy, PXRD analysis, XPS, and SEM-EDS studies show excellent stability as well as the strong affinity between -COOH active site and Sr2+. This strong coordination interaction guarantees a high adsorption capacity of 114 mg g−1 within 5 h (pH 5 and 298 K). Combined kinetic and thermodynamic studies show that the surface complexation is strong chemisorption and cost-effective spontaneous process (ΔG = −5.49 kJ mol−1~−2.16 kJ mol−1). The fact that UiO-66-(COOH)2 not only possesses a high adsorption capacity, but also enables selectivity to Sr2+ in the presence of similar radius ions Na+ and K+, prefigures its great potential for the practical treatment of radioactive Sr2+ in polluted water.
Highlights
Nuclear energy, due to its low-carbon and high-efficiency nature, is widely used in electric power, military, and industrial applications nowadays
We further expanded the application of UiO-66-(COOH)2 in radioactive contamination removal. We discovered that this carboxyl functionalized metal-organic frameworks (MOFs) can adsorb Sr2+, and explained the adsorption mechanism based on the results of the kinetic, thermodynamic, and characterization studies
The Fourier-transform infrared (FTIR) spectra of UiO-66-(COOH)2 featuring around 1700 cm−1 indicated that this material is abundant in carboxylic groups, providing the active sites in capturing metal ions (Figure 1a)
Summary
Due to its low-carbon and high-efficiency nature, is widely used in electric power, military, and industrial applications nowadays. 90 Sr, as representative radioactive contamination with strong beta-gamma/beta emitters, is of particular concern for its long half-life (t1/2 ~28.8 years). It is noteworthy that two carboxylate arms of H4 btec play the role of linkers, while the two remaining are non-bonded These free carboxylic acid groups are uniformly distributed throughout the MOF making them readily accessible for binding with cations without structure collapse [28]. We further expanded the application of UiO-66-(COOH) in radioactive contamination removal We discovered that this carboxyl functionalized MOF can adsorb Sr2+ , and explained the adsorption mechanism based on the results of the kinetic, thermodynamic, and characterization studies. We evidenced that it showed high adsorption capacity and selectivity even in the presence of disturbing ions, which makes it a good candidate in real-life applications
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
