Improving barium ion adsorption on two-dimensional titanium carbide by surface modification.

Recently, 2D-MXene materials have attracted much attention. However, their low adsorption capacities for metal ions have limited their application in nuclear wastewater disposal. Here, we describe the unprecedentedly high adsorption by Ti3C2Tx for the removal of radionuclides by a simple and efficient surface modification strategy. We have produced an Alk-Ti3C2Tx material possessing desirable properties such as wide layer spacing and abundant active adsorption sites, with excellent ability to remove barium ions from aqueous solution. Maximum Ba2+ adsorption by Alk-Ti3C2Tx is 46.46 mg g-1, almost three times higher than that of unmodified Ti3C2Tx and much higher than that reported in previous studies. The remarkable selectivity for the removal of Ba2+ from simulated mixed nuclear wastewater is highly desirable for application in environmental wastewater treatment.