Ding Rui, Zhu Yancheng, Jing Lu, Chen Shenghuang, Lu Jitao, Zhang Xiaomei
School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China.
Geological and Mineral Exploration Institute of Shandong Province, Jinan, Shandong Province 250100, China.
Int J Biol Macromol. 2024 Dec;282(Pt 5):137037. doi: 10.1016/j.ijbiomac.2024.137037. Epub 2024 Oct 30.
Developing candidate adsorbents with high capacity and selectivity for adsorption is a critical approach to recover gold from secondary sources such as electronic waste (e-waste). This measure not only contributes to the recycling of valuable resources but also benefits environment protection and mitigates the detriment to the ecosystem. Traditional covalent organic frameworks (COFs) have garnered great potential in various fields owing to their unique structures and innate functional sites. However, the construction of specific functionalized COFs and their application in efficient gold extraction are still in their nascent stages. Herein, inspired by the photo-induced thiol-ene click reaction, a novel chitosan-modified COFs material (DhaTab-V@chitosan-SH) was first demonstrated by choosing a precursor COF (DhaTab-V) abundant with vinyl groups to crosslink with a thiol-functionalized chitosan (chitosan-SH). Significantly, the coexistence of imine, amide, hydroxyl and thioether groups in the skeleton could serve as functional adsorption sites to combine with the Au (III) via electrostatic interaction and coordination, imparting DhaTab-V@chitosan-SH with prominent adsorption potential for swift, selective and efficient gold capture (970.15 mg·g). Additionally, DhaTab-V@chitosan-SH exhibited superior reusability, and realized real gold capture from the leaching solution of e-waste.
开发具有高吸附容量和选择性的候选吸附剂是从电子废物（e-waste）等二次资源中回收金的关键途径。这一举措不仅有助于宝贵资源的回收利用，还有利于环境保护并减轻对生态系统的损害。传统的共价有机框架（COFs）因其独特的结构和固有的功能位点在各个领域具有巨大潜力。然而，特定功能化COFs的构建及其在高效金提取中的应用仍处于起步阶段。在此，受光诱导硫醇-烯点击反应的启发，通过选择富含乙烯基的前体COF（DhaTab-V）与硫醇功能化壳聚糖（壳聚糖-SH）交联，首次展示了一种新型壳聚糖改性的COFs材料（DhaTab-V@壳聚糖-SH）。值得注意的是，骨架中亚胺、酰胺、羟基和硫醚基团的共存可作为功能吸附位点，通过静电相互作用和配位与Au（III）结合，赋予DhaTab-V@壳聚糖-SH快速、选择性和高效捕获金（970.15 mg·g）的突出吸附潜力。此外，DhaTab-V@壳聚糖-SH表现出优异的可重复使用性，并实现了从电子废物浸出液中实际捕获金。
