Incorporation of In₂S₃ Nanoparticles into a Metal–Organic Framework for Ultrafast Removal of Hg from Water

Considering rapidly rising Hg emission from industrial waste effluents, it is imperative to explore practical and effective adsorbents for Hg. Herein, a mild and facile method has been developed to confine ultrasmall In₂S₃ nanoparticles (about 2.5 nm) in the cavities of a MOF for the first time. The resulting composite (In₂S₃@MIL-101) can remove 99.95% of the Hg²⁺ from wastewater very efficiently in as short as 1 min with the highest distribution coefficient (2.2 × 10⁷ mL g^–1) among all MOF-based mercury adsorbents. It also displays excellent selectivity for Hg even when other interferential metal ions are present, and it can be reused with almost retained adsorption capacity. All of these features make the composite a potential adsorbent for Hg removal from industrial wastewater.