Efficient Adsorption of Ionic Liquids in Water Using -SO3H-Functionalized MIL-101(Cr): Adsorption Behavior and Mechanism

Ling Zhang; Shuai Ma; Sumei Hu; Qiao Qu; Chengxun Deng; Zhaoyi Xu; Xiaowei Liu

doi:10.1021/acs.langmuir.4c03790

Efficient Adsorption of Ionic Liquids in Water Using -SO₃H-Functionalized MIL-101(Cr): Adsorption Behavior and Mechanism

Langmuir. 2024 Dec 18. doi: 10.1021/acs.langmuir.4c03790. Online ahead of print.

Authors

Ling Zhang^{1

2}, Shuai Ma¹, Sumei Hu¹, Qiao Qu¹, Chengxun Deng^{1

2}, Zhaoyi Xu³, Xiaowei Liu^{1

2}

Affiliations

¹ School of Biology, Food, and Environment, Hefei University, Hefei 230601, China.
² International (Sino-German) Joint Research Center for Biomass of Anhui Province, Hefei 230601, China.
³ State Key Laboratory of Pollution Control and Resource Reuse, Jiangsu Key Laboratory of Vehicle Emissions Control, School of the Environment, Nanjing University, Nanjing 210023, China.

PMID: 39692146
DOI: 10.1021/acs.langmuir.4c03790

Abstract

With the increasing application of ionic liquids (ILs) in industrial areas, the removal of ILs from aqueous media has attracted considerable attention due to their potential environmental impact. In this study, we investigated the adsorption behavior and removal mechanism of ILs in water using the metal-organic framework material MIL-101(Cr) and its sulfonated derivative MIL-101(Cr)-SO₃H. It was observed that MIL-101(Cr)-SO₃H exhibited notably elevated adsorption capacity (1.19 mmol/g) and rapid adsorption kinetics (1.66 g/mmol·min^-1) for [C₄mim]Cl in comparison to its unmodified form, underscoring the impact of strategic sulfonation on enhancing adsorption. Also, MIL-101(Cr)-SO₃H showcased the effective removal of various ILs featuring diverse cations and varying anions, highlighting its broad-spectrum capture capacities. The adsorption process is less influenced by the type of cations and anions. In contrast, enhanced adsorption of [C₁₆mim]Cl by MIL-101(Cr)-SO₃H demonstrated that the length of the alkyl chain of ILs' cation exerted a more significant influence on the adsorption than the type of head and tail group. This enhancement is attributed to a synergistic interplay of pore filling, electrostatic interactions, hydrophobic interactions, and micelle enrichment. These findings provided valuable insights into optimizing the design of metal-organic framework materials for the efficient removal of IL pollutants.