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

• Published in: Water research (Oxford) 2023-10, Vol.245, p.120666-120666, Article 120666
• Main Authors: Liu, Yi-Lin, Zhang, Chao, Guo, Lulin, Zeng, Qingming, Wang, Rongzhong, Chen, Haodong, Zhang, Qingyan, Zeng, Qingyi
• Format: Article
• Language: English
• Subjects: Adsorption; MXene; Reduction; Uranium; Zero-valent copper
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/j.watres.2023.120666

•0D/2D nanocomposite of nZVC/Ti3C2 is prepared by a simple in situ chemical reduction method.•0D nZVC with a size of 5 nm are uniformly dispersed on ultrathin Ti3C2 MXene.•An exceptional adsorption capacity of up to 360 mg g–1 is obtained for U.•A large ratio of 73.6 % U (VI) is reduced into U (IV) under the reduction effect of nZVC.•Synergistic effect of Ti3C2 MXene and nZVC endows excellent adsorption ability. 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. [Display omitted] A novel 0D/2D nZVC/Ti3C2 nanocomposite is successfully synthesized and used as an effective adsorbent for U (VI) removal from wastewater based on the synergistic effect of Ti3C2 MXene and nZVC.