Synergistically adsorbing and reducing Uranium from water by a novel nano zero-valent copper/MXene 0D/2D...

Proper disposal of uranium-containing waste is of utmost importance for safeguarding the environment and human health. In this study, we proposed a novel zero-dimensional (0D)/two-dimensional (2D) nanocomposite material, nZVC/Ti₃C₂, composed of nano zero-valent copper (nZVC) nanoparticles loaded onto Ti₃C₂ MXene nanoflakes, which was prepared using a simple in situ chemical reduction method. The uniform dispersion of 0D nZVC nanoparticles, with a size of approximately 5 nm, onto the 2D ultrathin Ti₃C₂ MXene effectively prevented agglomeration and corrosion of nZVC. This unique configuration provided numerous adsorption sites for UO₂²⁺and facilitated a fascinating charge channel for reducing adsorbed UO₂²⁺ into low-mobilized UO₂ by nZVC. Under the synergistic effect of Ti₃C₂ MXene and nZVC, remarkable efficiency and selectivity of nZVC/Ti₃C₂ for U (VI) removal were demonstrated, which exhibited an exceptional adsorption capacity of up to 360 mg/g, coupled with a high removal efficiency of 97.5 % and rapid kinetics. Importantly, the presence of humic acid did not significantly affect the U (VI) removal efficiency of the composite because of the reduction effect of nZVC. The underlying mechanism of U (VI) removal was elucidated, revealing the involvement of reductive immobilization in the form of UO₂ (as high as 73.6 %), inner-sphere surface complexation, and hydrolytic precipitation. This mechanism was dependent on the availability of active nZVC and the solution's pH. These findings highlight the potential of nZVC/Ti₃C₂ composites as efficient decontaminants for radioactive wastewater, thus contributing to advancements in environmental remediation endeavors.