School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
Graduate School of Environmental Studies, Tohoku University, Sendai 980-8579, Japan.
J Hazard Mater. 2022 Mar 15;426:128062. doi: 10.1016/j.jhazmat.2021.128062. Epub 2021 Dec 10.
The phosphonate functionalized layered double hydroxide constructed through intercalation reaction, and efficiently applied to capture toxicant metal ions. The characterization results indicated that the functionalized composite with many functional groups has adsorption potential to heavy metals. The strong chelation of the phosphonate groups with heavy metal ions proved it an excellent adsorbent leading to a maximum adsorption capacity of 156.95 mg/g (Cr) and 198.34 mg/g (Cd) separately. The data of kinetics and isotherm revealed that the chelating adsorption was dominated by chemisorption and monolayer interaction. Notably, the spent adsorbent presented satisfactory reusability after six cycles. Furthermore, the Forcite simulation with the CLAYFF-CVFF force field implied that the critical mechanism for modifiers and the surface sites of the interlayer is electrostatic interaction. Our in-depth exploration in terms of the weak interactions not only demonstrated the strength and nature but also provided a novel way to intuitively capture the type of interactions that occurred around interesting regions. In the end, we made detailed investigations on the chelation mechanism, and the covalent nature played a leading role in the binding interaction. This work provides a valuable strategy for researchers to design novel materials in practice.
通过插层反应构建的膦酸功能化层状双氢氧化物，并有效地应用于捕获有毒金属离子。表征结果表明，具有多种官能团的功能化复合材料对重金属具有吸附潜力。膦酸基团与重金属离子的强螯合作用证明了它是一种优异的吸附剂，分别具有 156.95mg/g（Cr）和 198.34mg/g（Cd）的最大吸附容量。动力学和等温线数据表明，螯合吸附主要由化学吸附和单层相互作用控制。值得注意的是，经过六次循环后，使用过的吸附剂表现出令人满意的可重复使用性。此外，使用 CLAYFF-CVFF 力场的 Forcite 模拟表明，修饰剂和层间表面位点的关键机制是静电相互作用。我们对弱相互作用的深入研究不仅展示了相互作用的强度和性质，还提供了一种直观捕捉感兴趣区域周围发生的相互作用类型的新方法。最后，我们详细研究了螯合机理，发现共价性质在结合相互作用中起主导作用。这项工作为研究人员在实践中设计新型材料提供了有价值的策略。
