Fabrication of magnetic functionalised calix[4]arene composite for highly efficient and selective adsorption towards uranium(VI)

Environmental context Uranium-containing wastewaters have high potential to harm the environment and human health. We found that the combination of calix[4]arene with magnetic Fe3O4 particles produced good adsorption of uranium from wastewater. In addition, this material can be recycled and reused, so it has good prospects in practical applications for uranium remediation. A magnetic functionalised calix[4]arene composite consisting of Fe3O4 and calix[4]arene phosphonate derivative (CPD) was prepared through a facile self-assembly method. The composite was characterised by scanning electron microscopy (SEM), powder X-ray diffraction (PXRD) and Fourier transform infrared spectroscopy (FTIR). The as-synthesised Fe3O4/CPD composite was used to remove UVI from aqueous solutions under different conditions. Meanwhile, the adsorption isotherm, kinetics and thermodynamics were fitted and analysed. The results show that the Fe3O4/CPD composite may be a promising adsorption material for the separation and enrichment of UVI from aqueous solutions in the cleanup of environmental pollution.