Amidoximated CeMOFs superstructures with algae-removing properties for efficient uranium extraction from simulated seawater

Abstract

Metal-organic frameworks have great potential in the field of uranium extraction from seawater due to their abundant functional groups. The binding energy of different types of functional groups differ significantly from uranium, which mainly affects the efficiency of uranium extraction. MOFs materials self-assembled with nanostructures have better structural stability and can graft functional groups efficiently. By introducing functional groups into the ligands and organic modification, we successfully grafted amino and amidoxime groups into Cerium Terephthalate (CeBDC). The result exhibits that the aminated CeBDC (CeBDC-NH2) and amidoximated CeBDC (CeBDC-AO) make great strides in the maximum adsorption capacity and distribution coefficient (Kd). Among them, CeBDC-AO exhibit high adsorption amount of 723.8 mg g−1 and the Kd reached approximately 3.2 × 106 mL·g−1. Meanwhile, this nano-superstructure also has excellent algae removal ability, and the algae removal ability reaches 1.04 × 107 cells/mg in a static state. According to the density functional theory (DFT) calculation, amidoxime functional groups have the best adsorption effect in terms of surface electrostatic force. More broadly, this work has designed a new type of nano superstructure MOFs with little pollution, high efficiency and high selectivity, which can provide a new idea for the future work of extracting uranium from seawater.