AlNeyadi Shaikha S, Alhassani Mohammed T, Mukhtar Muneb R, Alblooshi Hamad K, Jama Sultan A, Al Mujaini Ibrahim, Aleissaee Ali S
Department of Chemistry College of Science, UAE University Al-Ain, 15551, United Arab Emirates.
Heliyon. 2024 Oct 11;10(20):e39042. doi: 10.1016/j.heliyon.2024.e39042. eCollection 2024 Oct 30.
The widespread use of imidacloprid (IMI) in pest control presents significant environmental challenges due to its persistence and low removal efficiency. This study introduces magnetic Covalent Organic Frameworks (COFs) functionalized with Fe₃O₄ nanoparticles (Fe₃O₄@HMN-COF, Fe₃O₄@MAN-COF, and Fe₃O₄@SIN-COF) as efficient adsorbents for IMI removal from water. These COFs, engineered with nitrogen-rich structures and extensive π-electron systems, achieve superior adsorption through π-π interactions, hydrophobic interactions, and hydrogen bonding. Characterization via FT-IR, XRD, and nitrogen sorption isotherms confirmed their high hydrophilicity, stability, and large surface areas. The magnetic properties of the COFs facilitated easy separation from water, enhancing practicality. Kinetic studies for all COFs indicated a pseudo-second-order model, suggesting chemisorption, with adsorption capacities of 600 mg/g for Fe₃O₄@HMN-COF, 480 mg/g for Fe₃O₄@MAN-COF, and 375 mg/g for Fe₃O₄@SIN-COF. Thermodynamic analyses revealed spontaneous and endothermic adsorption processes. Reusability tests showed minimal capacity loss over multiple cycles, underscoring their practical applicability. Practical tests in honey and fruit samples confirmed high efficacy, demonstrating the COFs' versatility. The study also optimized the photocatalytic degradation of imidacloprid using these COFs, with Fe₃O₄@HMN-COF achieving 98.5 % efficiency under optimal conditions (10 mg L IMI, 0.01 g catalyst dose, pH 11, 30 °C, UV light). These findings highlight the potential of magnetic COFs for sustainable environmental remediation of pesticide-contaminated water.
吡虫啉（IMI）在害虫防治中的广泛使用因其持久性和低去除效率而带来了重大的环境挑战。本研究引入了用四氧化三铁纳米颗粒功能化的磁性共价有机框架（COF）（Fe₃O₄@HMN-COF、Fe₃O₄@MAN-COF和Fe₃O₄@SIN-COF）作为从水中去除IMI的高效吸附剂。这些具有富氮结构和广泛π电子体系的COF通过π-π相互作用、疏水相互作用和氢键实现了卓越的吸附。通过傅里叶变换红外光谱（FT-IR）、X射线衍射（XRD）和氮吸附等温线表征证实了它们的高亲水性、稳定性和大表面积。COF的磁性便于从水中轻松分离，提高了实用性。所有COF的动力学研究表明符合伪二级模型，表明是化学吸附，Fe₃O₄@HMN-COF的吸附容量为600 mg/g，Fe₃O₄@MAN-COF为480 mg/g，Fe₃O₄@SIN-COF为375 mg/g。热力学分析表明吸附过程是自发的且吸热。可重复使用性测试表明在多个循环中容量损失最小，突出了它们的实际适用性。在蜂蜜和水果样品中的实际测试证实了高效性，证明了COF的多功能性。该研究还优化了使用这些COF对吡虫啉的光催化降解，在最佳条件下（10 mg/L IMI、0.01 g催化剂用量、pH 11、30°C、紫外光）Fe₃O₄@HMN-COF的降解效率达到98.5%。这些发现突出了磁性COF在农药污染水的可持续环境修复方面的潜力。
