Enhanced Uranium Extraction via Charge Dynamics and Interfacial Polarization in MoS2/GO Heterojunction Electrodes

The removal of uranyl ions (UO₂ ²⁺) from water is challenging due to their chemical stability, low concentrations, complex water matrix, and technical limitations in extraction and separation. Herein, a novel molybdenum disulfide/graphene oxide heterojunction (MoS₂/GO-H) is developed, serving as an effective electrode for capacitive deionization (CDI). By combining the inherent advantages of electroadsorption and electrocatalysis, an innovative electroadsorption-electrocatalysis system (EES) strategy is introduced. This system utilizes interface polarization at the MoS₂ and GO interface, creating an additional electric field that significantly influences carrier behavior. The MoS₂/GO-H electrode, with its extraordinary adsorption capacity of 805.57 mg g^-1 under optimal conditions, effectively treated uranium-laden wastewater from a mine, achieving over 90% removal efficiency despite the presence of numerous competing ions at concentrations significantly higher than UO₂ ²⁺. Employing density functional theory (DFT) and ab initio molecular dynamics (AIMD) simulations, it is found that the MoS₂/GO-H total charge density at the Fermi level, enhanced by interfacial polarization, surpasses that of separate MoS₂ and GO, markedly boosting conductivity and electrocatalytic effectiveness.