Efficient adsorption performance of uranium in wastewater by novel MXene material TiVCTx and its aerogel composites

Abstract

This work focuses on the application potential of novel MXene materials in the field of uranium-containing wastewater adsorption, particularly addressing gaps in existing research. Ultra-thin layered TiVCT_x was selected as the core adsorbent to thoroughly investigate its adsorption performance of uranium(U(VI))-containing wastewater. By compounding with sodium alginate, we successfully prepared easily recoverable aerogel beads and evaluated their adsorption capacity for ultra-low concentrations of U(VI) in seawater. The findings of this study reveal that TiVCT_x exhibits optimal adsorption capacity for U(VI) in a weakly acidic environment with a pH of 5.59, and its maximum adsorption capacity for U(VI) reaches up to 336 mg g⁻¹, demonstrating superior performance when it comes to other MXene materials. Further research reveals that the adsorption mechanism involves the synergistic effect of electrostatic adsorption and reduction adsorption, exhibiting monolayer adsorption characteristics, and the adsorption process is a spontaneous endothermic reaction. Notably, in simulated complex seawater environments, even when the U(VI) concentration is as low as, for instance, 3.3 μg L⁻¹, 50 mg of aerogel beads can still achieve an adsorption capacity of 3.89 mg g⁻¹ for 60 L of seawater. These findings underscore the outstanding performance of TiVCT_x as a novel MXene material in U(VI) adsorption and its broad potential for practical applications.