Fabrication of Magnetic Fe/Zn Layered Double Oxide@Carbon Nanotube Composites and Their Application for U(VI) and 241Am(III) Removal

Magnetic Fe/Zn layered double oxide decorated carbon nanotubes (M-Fe/Zn-LDO@CNTs) composites were synthesized via a hydrothermal method with further calcination treatment. The fabricated M-Fe/Zn-LDO@CNTs were characterized by X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, UV–vis spectroscopy, scanning electron microscopy, and transmission electron microscopy and then applied for U(VI) elimination under diversiform experimental conditions, such as pH, temperature, ionic strength, contact time, and coexisting ions. The experimental results demonstrated that the U(VI) adsorption performance of M-Fe/Zn-LDO@CNTs was much higher than bare CNTs. The thermodynamic parameters revealed that U(VI) adsorption on M-Fe/Zn-LDO@CNTs was endothermic and spontaneous. More importantly, the adsorption performance of U(VI) on M-Fe/Zn-LDO@CNTs was still higher than ∼89% after five cycles. Furthermore, ∼95.9% of 241Am(III) could be removed by M-Fe/Zn-LDO@CNTs from solution at pH = 8.0, which confirmed that M-Fe/Zn-LDO@CNTs was an excellent material for efficient removal of long-lived lanthanides and actinides from environmental aqueous solutions in radionuclides’ pollution remediation.