Preparation of Novel Bifunctional Magnetic Tubular Nanofibers and Their Application in Efficient and Irreversible Uranium Trap from Aqueous Solution

A low-cost and efficient material is highly attractive for the removal of radioactive metal ions from aqueous solutions. However, it is highly required and still challenging. In this work, novel bifunctional magnetic tubular nanofibers (FMTnF) are prepared from α,α′-dichloro-p-xylene via self-polymerization by the two-oil-solvent method. The polymerized material is followed by carbonization. The carbonized material experienced bifunctionalization, first, grafting of sulphonic (-SO₃H) and carboxylic (-COOH) groups and second, loading of Fe₃O₄ for the preparation of sulphonic magnetic tubular nanofibers (FMTnF-SO₃H) and carboxyl magnetic tubular nanofibers (FMTnF-COOH). The average diameter of FMTnF-SO₃H and FMTnF-COOH is about 160 nm, and the saturation magnetization values are 21.61 and 19.44 emu g^-1, respectively. The adsorption performances of these two adsorbents are studied and compared for the removal of U(VI) from aqueous solution. Fourier transform infrared and X-ray photoelectron spectroscopy characterizations combined with isothermal studies confirmed that the interaction of U(VI) with active sites of FMTnF-SO₃H and FMTnF-COOH is usually through coordination complexation. The maximum adsorption capacities of FMTnF-SO₃H and FMTnF-COOH are 955.6993 and 980.3921 mg g^-1, respectively, at pH = 8. Moreover, the high adsorption efficiency can reach 85 ± 0.5% at low concentration (3 μg L^-1). Excellent regeneration and reusability of FMTnF-SO₃H and FMTnF-COOH offered long-term usage to decrease cost for U(VI) adsorption from seawater/wastewater treatment.