Layered Metal Sulfides Capture Uranium from Seawater

TLDR

Uranium is a key nuclear fuel and a toxic heavy metal, yet existing water‑removal methods suffer from limited pH range, salt tolerance, and high cost. The layered sulfide ion exchanger K₂MnSn₂S₆ (KMS‑1) selectively and rapidly captures both high‑level and trace uranium from seawater, outperforming current techniques and showing strong potential for uranium remediation and extraction.

Abstract

Uranium is the main source for nuclear energy but also one of the most toxic heavy metals. The current methods for uranium removal from water present limitations, such as narrow pH operating range, limited tolerance to high salt concentrations, or/and high cost. We show here that a layered sulfide ion exchanger K2MnSn2S6 (KMS-1) overcomes these limitations and is exceptionally capable in selectively and rapidly sequestering high (ppm) as well as trace (ppb) quantities of UO22+ under a variety of conditions, including seawater. KMS-1 can efficiently absorb the naturally occurring U traces in seawater samples. The results presented here reveal the exceptional potential of sulfide-based ion-exchangers for remediating of uranium-containing wastes and groundwater and for extracting uranium from the sea.