Antibacterial MXene composite with excellent U/V selectivity for uranium extraction

Abstract

Uranium, as a radioactive element, is the source of utilizable energy for mankind in the future. Large quantities of uranium resources are contained in seawater, so uranium extraction from seawater is undoubtedly the most feasible method. However, the presence of competitive ions such as vanadium hinders the efficient extraction of uranium, which is currently a challenge that needs to be solved. Here, silane coupling agent (KH550) was grafted onto two-dimensional metal carbide (MXene). Subsequently, salicylaldoxime (SA) was deposited onto MXene particles using self-polymerization of dopamine (DA) to prepare PDA/SA deposited MXene composite grafted with KH550 (PDA/SA/MXene-KH550). The adsorbent exhibited excellent selectivity for uranium ions with a uranium/vanadium selectivity ratio of 4.8. In antibacterial experiments, the PDA/SA/MXene-KH550 composite showed excellent antibacterial performance against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), demonstrating the ability to adapt to complex marine microbial contamination. In addition, the maximum experimental uranium adsorption capacity of the composite was 332.3 mg/g, following the pseudo-second-order kinetic model and the Langmuir isotherm model. After five adsorption-desorption cycles, the elution efficiency of PDA/SA/MXene-KH550 for uranium can still reach 74.7 %, which demonstrated that the adsorbent had superior stability and regeneration ability, providing the possibility for actual enrichment of uranium.