American Chemical Society
es5b02679_si_001.pdf (2.12 MB)

Different Interaction Mechanisms of Eu(III) and 243Am(III) with Carbon Nanotubes Studied by Batch, Spectroscopy Technique and Theoretical Calculation

Download (2.12 MB)
journal contribution
posted on 2015-10-06, 00:00 authored by Xiangxue Wang, Shubin Yang, Weiqun Shi, Jiaxing Li, Tasawar Hayat, Xiangke Wang
Herein the sorption of Eu­(III) and 243Am­(III) on multiwalled carbon nanotubes (CNTs) are studied, and the results show that Eu­(III) and 243Am­(III) could form strong inner-sphere surface complexes on CNT surfaces. However, the sorption of Eu­(III) on CNTs is stronger than that of 243Am­(III) on CNTs, suggesting the difference in the interaction mechanisms or properties of Eu­(III) and 243Am­(III) with CNTs, which is quite different from the results of Eu­(III) and 243Am­(III) interaction on natural clay minerals and oxides. On the basis of the results of density functional theory calculations, the binding energies of Eu­(III) on CNTs are much higher than those of 243Am­(III) on CNTs, indicating that Eu­(III) could form stronger complexes with the oxygen-containing functional groups of CNTs than 243Am­(III), which is in good agreement with the experimental results of higher sorption capacity of CNTs for Eu­(III). The oxygen-containing functional groups contribute significantly to the uptake of Eu­(III) and 243Am­(III), and the binding affinity increases in the order of SOH < SCOOH < SCOO. This paper highlights the interaction mechanism of Eu­(III) and 243Am­(III) with different oxygen-containing functional groups of CNTs, which plays an important role for the potential application of CNTs in the preconcentration, removal, and separation of trivalent lanthanides and actinides in environmental pollution cleanup.