Modeling Uranyl Adsorption on MoS₂/Mo₂CT Heterostructures Using DFT and BOMD Methods

Area of Science:

• Materials Science
• Environmental Chemistry
• Computational Chemistry

Background:

• Uranium-bearing wastewater poses significant ecological risks due to high radiotoxicity.
• Effective radionuclide removal from wastewater requires advanced adsorption materials.

Purpose of the Study:

• Investigate uranyl adsorption behavior on MoS2/Mo2CTx heterostructures.
• Elucidate adsorption mechanisms in both gas and aqueous phases.
• Explore the potential of this heterostructure as a nanosorbent for uranyl removal.

Main Methods:

• Density Functional Theory (DFT) simulations.
• Born-Oppenheimer molecular dynamics simulations.
• Analysis of adsorption sites, binding configurations, and interactions (coordination, H-bond, van der Waals).

Main Results:

• Uranyl ions preferentially adsorb at deprotonated O sites (Mo2COH surface) and S sites (MoS2 surface), forming bidentate configurations.
• The Mo2COH surface exhibits strong reducibility, reducing U(VI) to U(IV) at room temperature.
• Uranyl complexes exhibit mobility on the MoS2 surface, while coordination numbers remain consistent across surfaces.

Conclusions:

• MoS2/Mo2CTx heterostructures show promise as novel nanosorbents for uranyl removal from wastewater.
• Computational simulations provide crucial mechanistic insights into uranyl adsorption processes.
• This study complements experimental research and offers a pathway for developing advanced wastewater treatment technologies.