Ionic liquid-based materials as adsorbents for water purification: a review

In this article, more than fifty publications (2021–2025) have been reviewed to analyze the adsorption behaviors of ionic liquid-based materials for different water contaminants under varied environmental conditions. Thus, the trends observed across the removal performances for different pollutant classes are depicted, and the common interaction mechanisms related to material reusability as an adsorbent are discussed. The main observations we drew from this review are as follows: (i) Ionic liquid-based materials show significant promise as effective scavengers of aqueous pollutants by adsorption because they have relatively high adsorption capacities and good recyclability of five cycles of reuse and more, (ii) support-immobilized ionic liquid-based materials show enhanced material stability, reusability, and adsorption efficiency for aqueous adsorbates, (iii) however, there are key challenges that persist, and these cover aspects related to ionic liquid stability, environmental safety, and real-water applicability of these ionic liquid-based materials under harsh environmental conditions, and (iv) lifecycle-based techno-economic studies of ionic liquid-based adsorption units is necessary if ionic liquid-based materials are being contemplated for industrial water treatment processes. This review also identifies current research gaps around the development of more efficient, durable, and sustainable ionic liquid-based adsorption systems for water purification. The major implication of developing ionic liquid-based aqueous-phase adsorbents is to promote green chemistry at the laboratory scale and aspire for green chemical process engineering in real-world water remediation systems using such a material that has the requisite selectivity and durability.

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