Removal of Uranyl(VI)\nwith Two–Dimensional\nMg(OH)<sub>2</sub>‑Based Heterojunctions: A Density Functional\nTheory Insight

With the development of nuclear energy, a large number\nof radionuclides\nare inevitably released into the natural environment. An important\nstrategy for the management of radioactive nuclides in complex environments\nis the development of efficient nanomaterials. In this work, heterojunctions\nassembled with monolayers of Mg(OH)<sub>2</sub> and two-dimensional\n(2D) sheets (graphene, 1T–MoS<sub>2</sub>, WSe<sub>2</sub>,\nTi<sub>2</sub>CF<sub>2</sub>, Ti<sub>2</sub>CO<sub>2</sub>) were designed\nfor the removal of uranyl(VI). Our results indicate that uranyl(VI)\nprefers to be adsorbed on the Mg(OH)<sub>2</sub> side of the heterojunctions\nin the inner-sphere binding mode. Various chemical bond analyses were\nemployed to reveal the bonding natures of uranyl(VI) with the heterojunctions.\nThe adsorption of uranyl(VI) is enhanced in the explicit solvation\nenvironment due to the interactions of uranyl(VI) and surrounding\nH<sub>2</sub>O molecules. The diffusion energy barriers of uranyl(VI)\non the heterojunctions were assessed. AIMD simulations at ambient\ntemperature indicate that uranyl(VI) can efficiently anchor on the\nheterojunction surface in an aqueous environment. This study may provide\ntheoretical support for the development of novel nanomaterials for\nthe removal of radionuclides.