Removal of Uranyl(VI) with Two–Dimensional Mg(OH)₂-Based Heterojunctions: A Density Functional Theory Insight

With the development of nuclear energy, a large number of radionuclides are inevitably released into the natural environment. An important strategy for the management of radioactive nuclides in complex environments is the development of efficient nanomaterials. In this work, heterojunctions assembled with monolayers of Mg(OH)2 and two-dimensional (2D) sheets (graphene, 1T–MoS2, WSe2, Ti2CF2, Ti2CO2) were designed for the removal of uranyl(VI). Our results indicate that uranyl(VI) prefers to be adsorbed on the Mg(OH)2 side of the heterojunctions in the inner-sphere binding mode. Various chemical bond analyses were employed to reveal the bonding natures of uranyl(VI) with the heterojunctions. The adsorption of uranyl(VI) is enhanced in the explicit solvation environment due to the interactions of uranyl(VI) and surrounding H2O molecules. The diffusion energy barriers of uranyl(VI) on the heterojunctions were assessed. AIMD simulations at ambient temperature indicate that uranyl(VI) can efficiently anchor on the heterojunction surface in an aqueous environment. This study may provide theoretical support for the development of novel nanomaterials for the removal of radionuclides.