In situ synthesis of Ni0Fe0-anchored ZnS nanosheets for efficient synergistic capture and immobilization of U(VI) and Se(IV).

Designing advanced adsorbents is indispensable for the effective remediation of uranium and selenium contamination in aquatic environments. Herein, a bimetallic Ni0Fe0-ZnS nanocomposite was prepared by anchoring zero-valent Ni and Fe nanoparticles onto two-dimensional ZnS nanosheets through an in situ liquid-phase strategy. The incorporation of Ni0/Fe0 preserved the ZnS nanosheet architecture, mitigated nanoparticle aggregation, and generated abundant interfacial reactive sites for superior contaminant removal. Batch experiments revealed that the maximum U(VI) removal capacity of Ni0Fe0-ZnS reached 1802.6 mg/g at 318 K. The Ni0Fe0-ZnS showed exceptional tolerance toward humic acid, coexisting ions, and varying ionic strength, while maintaining robust performance in real water matrices such as tap water and seawater. Notably, Ni0Fe0-ZnS enabled the efficient simultaneous sequestration of U(VI) and Se(IV) in binary systems, where the removal performance of Se(IV) was substantially enhanced compared with that in the single Se(IV) system. Mechanistic analyses revealed that the removal occurs via a synergistic pathway involving surface adsorption, chemical reduction, and the formation of stable precipitates. This study presents a viable material-engineering strategy for fabricating high-performance bimetallic adsorbents and offers a prospective solution for treating complex radioactive wastewater co-contaminated with uranium and selenium.