Carbon nano tubes functionalized with novel functional group- amido-amine for sorption of actinides

Highlights: • Novel amido-amine functionalized MWCNT was synthesized and characterized. • The synthesized MWCNT-AA was found to be an effective sorbent for radionuclides. • Sorption was found to be dependent on pH and ionic strength of the medium. • Sorption efficiency was found to be following the trend: U(VI) > Am(III) > Eu(III). • DFT calculations showed the reason behind the trend. - Abstract: The manuscript presents the results on the sorption of U(VI), Am(III) & Eu(III) from pH medium by a novel amido-amine functionalized multiwalled carbon nanotube (MWCNT). The novel functional group was introduced in the MWCNT by two step processes and characterized by various instrumental techniques like Scanning Electron Microscopy (SEM), Raman and X-ray Photoelectron Spectroscopy (XPS). The sorption process was found to be highly dependent on the pH of the solution with maximum sorption for both 233U, 241Am & 152+154Eu at pH 7.0. Kinetics of sorption was found to be fast with equilibrium reached in ∼15 min and the sorption was found to be following pseudo 2nd order kinetics for the radionuclides. The sorption for both 233U and 152+154Eu followed Langmuir sorption model with maximum sorption capacity of 20.66 mg/g and 16.1 mg/g respectively. This has been explained by DFT calculations which shows that more negative solvation energy of U(VI) compared to Am(III) and Eu(III) and stronger U-MWCNT-AA complex is responsible for higher sorption capacity of U(VI) compared to Am(III) and Eu(III).The synthesized amido-amine functionalized MWCNT is a very promising candidate for removal of actinides and lanthanides from waste water solution with high efficiency