Enhanced degradation of Ionic liquid 1-n-Butyl-3-Methylimidazolium chloride by visible Light-Promoted Fe-MOF-activated Peroxydisulfate: A comparative study with DFT and Eco-Toxicity assessment

Ionic liquids (ILs) are increasingly adopted in various applications, leading to their release into the water environment, where they pose potential threats to ecology in view of toxicities. In order to remove 1-n-Butyl-3-Methylimidazolium (BMI) chloride, a well-known model IL, from water, urgent and crucial techniques are needed. Peroxydisulfate (PDS) activated by heterogeneous catalysts is useful for BMI degradation; nonetheless, heterogeneously activated PDS has been utilized in very few studies. A Fe-based metal–organic framework, Fe-2-aminobenzene-1,4-dicarboxylic acid (FeBDC-NH₂), is suggested here for serving as an activator because of its Fe sites, high surface areas, porosities, and visible-light responsive photocatalytic activity. The structure–property relationship of FeBDC-NH₂ in PDS activation is compared to that of Fe-Benzene-1,4-dicarboxylic acid (FeBDC), and both are found to activate PDS to degrade BMI. FeBDC-NH₂, however, significantly accelerated BMI degradation when exposed to visible light. Compared to activation energies reported by other oxidation approaches, the activation energy of BMI degradation is considerably lower. Through theoretical DFT calculations, the mechanism and pathway of BMI degradation by FeBDC-NH₂/PDS are examined. The eco-toxicities of BMI degradation intermediates are researched to understand the impact of BMI degradation on the environment. These analyses show that the toxicities of BMI are effectively reduced by FeBDC-NH₂-activated PDS under light irradiation and that the final derivatives of BMI produced during the degradation process are non-harmful in terms of both acute and chronic toxicities.