Developing sustainable, efficient, and selective gold recovery technology is essential to implement the valorization of complementary alternative sources for this precious metal, such as spent e-waste, and to preserve the environment. The main challenge in recovering gold from liquors obtained from leached waste electronics is the low concentration of this precious metal compared to impurities. Here, we report the preparation of a novel multivariate biological metal–organic framework (MTV-BioMOF) as a potential material for the selective recovery of gold metal ions from water, even in the presence of other interfering metals. Moreover, MTV-BioMOF can be incorporated within single-walled carbon nanotube buckypapers (SWCNT-BP) to yield an MTV-BioMOF@HS-SWCNT-BP composite, which combines enhanced mechanical properties and high chemical stability. The thiol-functionalized SWCNT-BP surface and the presence of thioether groups evenly decorating the MTV-BioMOF channels shape a task-specific functional environment that boosts the interactions with gold metal ions. The efficiency of gold recovery reaches values up to 99.5% when MTV-BioMOF@SWCNT-BP is used as an adsorbent for treating Au(III) in very diluted solutions (initial concentration of 5 ppm). This high recovery efficiency, with values as high as 98.0%, is maintained even in the presence of competing metal cations, also demonstrating a noticeable selectivity. This composite material represents a promising paradigm for the selective extraction, enrichment, and purification of gold.

中文翻译：

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用于金回收的硫功能化单壁碳纳米管巴基纸/MTV-生物金属-有机框架纳米复合材料


开发可持续、高效和选择性的黄金回收技术对于实现这种贵金属的补充替代来源（例如废电子废物）的增值以及保护环境至关重要。从浸出的废弃电子产品中获得的液体中回收黄金的主要挑战是与杂质相比，这种贵金属的浓度较低。在这里，我们报告了一种新型多元生物金属有机框架（MTV-BioMOF）的制备，作为一种潜在材料，即使在存在其他干扰金属的情况下，也可以从水中选择性回收金金属离子。此外，MTV-BioMOF 可以合并到单壁碳纳米管巴基纸 (SWCNT-BP) 中，形成 MTV-BioMOF@HS-SWCNT-BP 复合材料，该复合材料结合了增强的机械性能和高化学稳定性。硫醇功能化的 SWCNT-BP 表面和均匀装饰 MTV-BioMOF 通道的硫醚基团的存在形成了一个特定任务的功能环境，可增强与金金属离子的相互作用。当MTV-BioMOF@SWCNT-BP用作吸附剂处理非常稀的溶液（初始浓度为5 ppm）中的Au(III)时，金回收率高达99.5%。即使存在竞争性金属阳离子，也能保持高达 98.0% 的高回收效率，也表现出显着的选择性。这种复合材料代表了选择性提取、富集和纯化金的有前景的范例。