Work

Stepwise Extraction of Metal Cations From Aqueous Solution Using Polyoxometalate‐Based Ionic Liquids

Year: 2026

Type: article

Abstract: ABSTRACT Waste electronic products (e‐waste) are a valuable source for technologically important metals such as copper, gold or rare earth elements. However, separation of these metals from complex waste mixtures is difficult, and new methods are required to address this challenge. Here, we show how polyoxometalate‐ionic liquids (POM‐ILs) can be used for the selective, biphasic liquid‐liquid extraction of metal cations from aqueous solutions simulating acid leachates of e‐waste. Several organo‐soluble POM‐ILs featuring metal‐binding sites at the POM anion were designed to enable biphasic liquid‐liquid extraction of aqueous leachates. Extraction experiments were carried out using Cu(II), Au(III), In(III), La(III), and Nd(III) as models for main group metal, transition metal, and lanthanide metal cations. Based on an optimized extraction protocol, high, often quantitative extraction efficiencies were observed, and the roles of the cation and anion of the POM‐IL were mechanistically studied. The stepwise, selective extraction of individual metal cations from multi‐cation mixtures was demonstrated to highlight the scope of the new extraction procedure. The work lays the foundation for the development of sustainable metal extraction and recovery processes using POM‐ILs.

Source: Advanced Sustainable Systems

DOI: 10.1002/adsu.70683

Authors: Nico Achenbach, Sarra Rahali, Boris Mashtakov, Carsten Streb

Institution: Johannes Gutenberg University Mainz

Language: English

Topic: Extraction and Separation Processes

Subfield: Metals and Alloys

Field: Materials Science

Domain: Physical Sciences

SDGs: Responsible consumption and production, Clean water and sanitation

Open Access status: hybrid

Estimated APC paid: $4,430