Highly Efficient Removal of Neonicotinoid Insecticides by Thioether-Based (Multivariate) Metal-Organic Frameworks

Area of Science:

• Materials Science
• Environmental Chemistry
• Supramolecular Chemistry

Background:

• Agrochemicals, particularly neonicotinoid insecticides, pose significant risks to aquatic ecosystems and human health.
• Effective removal strategies are crucial to mitigate the environmental impact of these contaminants.
• Existing water treatment methods often face challenges in efficiency and environmental compatibility.

Purpose of the Study:

• To develop and evaluate novel, eco-friendly adsorbents for the removal of neonicotinoid insecticides from water.
• To investigate the efficacy of a family of water-stable, isoreticular metal-organic frameworks (MOFs) derived from amino acids.
• To identify specific MOF structures with superior adsorption capabilities for targeted insecticide removal.

Main Methods:

• Synthesis of five isoreticular metal-organic frameworks (MOFs) using amino acid precursors.
• Characterization of MOF stability in aqueous environments.
• Testing the adsorption efficiency of MOFs for five common neonicotinoid insecticides (thiamethoxam, clothianidin, imidacloprid, acetamiprid, and thiacloprid).
• Evaluation of a specific multivariate MOF (compound 5) under dynamic solid-phase extraction conditions.

Main Results:

• Three of the synthesized MOFs, containing thioether-based residues, exhibited remarkable removal efficiencies for neonicotinoid insecticides.
• The novel multivariate MOF (compound 5) demonstrated exceptional performance, achieving 100% removal of acetamiprid and thiacloprid in under 30 seconds.
• Compound 5 features functional channels decorated with thioalkyl chains derived from l-methionine and l-methylcysteine, contributing to its high adsorption capacity.
• The MOFs displayed high stability under environmental conditions.

Conclusions:

• Amino acid-derived, water-stable MOFs are highly effective adsorbents for removing neonicotinoid insecticides from water.
• The novel multivariate MOF (compound 5) represents a promising, sustainable solution for water remediation due to its outstanding efficiency, stability, and straightforward synthesis.
• This research offers a viable pathway for developing advanced materials to combat water pollution from agricultural chemicals.