Department of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang 414006, Hunan, China.
Langmuir. 2022 Jul 26;38(29):8954-8963. doi: 10.1021/acs.langmuir.2c01137. Epub 2022 Jul 13.
The efficient enrichment and selection of Au are crucial for gold recovery. The adsorption technology is considered to have potential due to the advantages of operation simplicity and green processability. Nevertheless, the poor Au selectivity at low concentrations in complex solutions limits the further application of the adsorption technology. In this work, a novel Cr-based MOF adsorbent was successfully synthesized using 1,2,4-triazole and 4-aminobenzoic acid as ligands. Benefitting from the surface positive charge and extensive chelation and reduction sites, the novel Cr-based MOF exhibited a total adsorption capacity of up to 357 mg/g and excellent adsorption selectivity toward Au(III) in the complex metal mixed solutions, such as simulated sewage ash waste liquid and actual e-waste leachate. Furthermore, the adsorption kinetics, isotherms, and thermodynamics were discussed in depth for investigating the adsorption mechanisms of the MOF. The PXRD and XPS analyses reveal that the adsorption process involves complexation, redox, and electrostatic interactions. We believe that this study of novel Cr-based MOF adsorbents for efficient Au adsorption is meaningful for further application in the gold recovery technology from e-waste.
高效地富集和选择 Au 对于金的回收至关重要。吸附技术由于操作简单和绿色工艺的优势被认为具有潜力。然而，在复杂溶液中低浓度下 Au 选择性差限制了吸附技术的进一步应用。在这项工作中，使用 1,2,4-三唑和 4-氨基苯甲酸作为配体成功合成了一种新型 Cr 基 MOF 吸附剂。得益于表面正电荷和广泛的螯合及还原位点，新型 Cr 基 MOF 在复杂金属混合溶液（如模拟污水灰废液和实际电子废物浸出液）中对 Au(III)表现出高达 357 mg/g 的总吸附容量和优异的吸附选择性。此外，还深入讨论了吸附动力学、等温线和热力学，以研究 MOF 的吸附机制。PXRD 和 XPS 分析表明，吸附过程涉及络合、氧化还原和静电相互作用。我们相信，这项关于新型 Cr 基 MOF 吸附剂用于高效 Au 吸附的研究对于进一步应用于从电子废物中回收金的技术具有重要意义。
