High-capacity Mo₃S₁₃-LDH for selective uranium extraction from seawater

Abstract

The growing demand for nuclear energy has intensified concerns over uranium (U) resource scarcity and the risks of environmental contamination, highlighting the urgency of developing efficient U separation technologies. Herein, we present a scalable synthesis of Mo₃S₁₃-intercalated layered double hydroxides (Mo₃S₁₃-LDH) by polysulfide clusters incorporation into MgAl-LDH. The resulting Mo₃S₁₃-LDH exhibits high affinity for U, achieving a high U adsorption capacity of 854.7 mg·g⁻¹, rapid kinetics with saturation achieved within 2 h, and a removal efficiency exceeding 99.99% across a wide U concentration range (1–500 mg·L⁻¹). Moreover, the Mo₃S₁₃-LDH retains high selectivity for U even in multi-ion conditions, as reflected by distribution coefficients ranging from 10⁷ to 10⁹ mL·g⁻¹. Mechanistic analysis reveals that the U removal process involves electron transfer from sulfur to molybdenum, coupled with the reduction of U(VI) to U(IV). In simulated marine contamination experiments using water from the Yellow Sea and Bohai Seas spiked with 3 mg·L⁻¹ U(VI), Mo₃S₁₃-LDH achieved 77.9% U removal while maintaining high selectivity amid a complex ionic background. These results position Mo₃S₁₃-LDH as a promising material for selective U recovery and emergency remediation in challenging aquatic environments. Beyond its high efficiency and practical applicability, Mo₃S₁₃-LDH represents a robust and scalable strategy for mitigating U contamination in diverse environmental contexts.