Cu-BTC Metal–Organic Framework@Ti3C2Tx MXene for Radioactive Uranium Sequestration in an Aqueous Solution

Radioactive uranium is an essential element for nuclear power production, yet the discharge of untreated uranium-containing wastewater presents a significant environmental challenge. In this study, a Cu-BTC metal–organic framework (MOF) decorated Ti₃C₂T_x MXene (Cu-BTC@MXene) was synthesized via a one-step co-precipitation method for uranium removal from aqueous solutions. The combination of Cu-BTC and Ti₃C₂T_x MXene demonstrated improved uranium adsorption capacity compared to pristine Ti₃C₂T_x MXene and Cu-BTC alone, owing to an increased specific surface area (1494.1 m² g⁻¹) and the introduction of various functional groups. The Cu-BTC@MXene achieved complete uranium removal within 60 min, exhibiting a significantly higher uranium removal efficiency than previously reported MXene-based adsorbents. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses revealed that the superior adsorption performance of Cu-BTC@MXene was primarily attributed to electrostatic attraction, the complexation of −COOH groups and Ti sites, ion exchange between copper and uranium, and cation–π interactions. The adsorption behavior conformed to pseudo-second-order kinetics and the Freundlich isotherm model, indicating that chemisorption is the dominant mechanism in uranium adsorption by Cu-BTC@MXene. Additionally, Cu-BTC@MXene maintained high uranium adsorption efficiency in the presence of various ions and across different water resources. These findings highlight the potential of the synthesized Cu-BTC@MXene as a promising adsorbent for the treatment of uranium-containing wastewater.