基于大面积石墨烯基复合纸，用于从电子垃圾中高效回收黄金

摘要：含有贵金属的电子垃圾日益增多，这就要求开发高效的回收策略，从电子垃圾中回收黄金。本文，清华大学深圳国际研究生院苏阳副教授、Qing Zhang，深圳理工大学成会明教授等在《EcoMat》期刊发表名为“A Large-Area Graphene-Based

1成果简介

含有贵金属的电子垃圾日益增多，这就要求开发高效的回收策略，从电子垃圾中回收黄金。本文，清华大学深圳国际研究生院苏阳副教授、Qing Zhang，深圳理工大学成会明教授等在《EcoMat》期刊发表名为“A Large-Area Graphene-Based Composite Paper for Efficient Gold Extraction From E-Waste and Its Reuse”的论文，研究提出了可扩展的rGO/纤维素复合纸制造方法（最多3600 cm2），其rGO面积密度高达7.5g/m2，并将其用作提取金的高效大面积吸附剂。所制备的rGO@纤维素复合材料具有出色的金萃取能力，在25°C和60°C温度条件下分别达到20 g/m2和36.3 g/m2，这相当于2662 mg/g和 4833 mg/g的高重量容量。

从含有13种金属的电子废弃物中提取黄金时，rGO@纤维素对黄金保持精确的选择性，提取效率高达 99.6%，为从电子废弃物中可持续地回收黄金提供了一条可行的途径。此外，rGO@纤维素回收的金还可重新用于光热蒸汽发电和催化降解环境污染物，这证明了其在黄金提取之外的多种环境应用潜力。这项工作为电子废物回收提供了一种可持续的方法，为应对环境挑战提供了一条途径，同时促进了资源的循环利用。

2图文导读

图1、(a) Schematic illustration of the fabrication process of rGO@cellulose and its gold extraction process, the lower panel shows the corresponding pictures of the materials used in each step. (b) Photographs of large-area rGO@cellulose.

图2、(a) Effect of reduction temperature on the C/O ratio of rGO. (b) Effect of reduction temperature on the gold extraction capacity of rGO@cellulose. (c–e) C1s XPS spectra of (c) GO, (d) rGO reduced at 210°C, and (e) rGO reduced at 350°C. (f–h) SEM images of different samples after gold extraction. (f) GO@cellulose and (g) rGO@cellulose reduced at 210°C. Scale bar: 100 μm. Inset: SEM image of Au particles on rGO@cellulose. (h) rGO@cellulose reduced at 350°C.

图3、(a, b) Influences of rGO areal density on (a) the extraction capacity (mg/g) and (b) areal extraction capacity of rGO@cellulose. (c) Comparison of gold extraction capacity by rGO@cellulose, VC-rGO paper, and rGO aerogel.

图4、Effect of the initial concentration (a), extraction time (b), and extraction temperature (c) on the gold extraction capacity of rGO@cellulose. (c) Inset: Arrhenius-type plots of rate constants of gold extracted by rGO@cellulose. (d) XRD pattern of Au@rGO@cellulose (e) 4f XPS spectrum of gold nanoparticles on rGO. Black dotted curve: Raw data with the fitting envelope in purple.

图5、(a) The composition of the e-waste leachate before and after extraction by rGO@cellulose. (b) The change of extraction efficiency and permeance with increasing the amount of the 10 ppm Au solution filtrated through.

图6、Reuse of Au@rGO@cellulose for photothermal steam generation and catalysis application. (a) Comparison of photothermal steam generation rates using various photothermal materials. The evaporation rate of “water” is the data obtained without using any photothermal material. Inset: Schematic illustration of photothermal steam generation device. (b) Stability of the continuous steam generation performance using Au@rGO@cellulose. (c, d) UV–vis spectra of 4-NP solution during catalytic conversion by (c) rGO@cellulose and (d) Au@rGO@cellulose. Plot of ln(Ct/C0) of 4-NP against time for the rGO@celluloses and Au@rGO@cellulose. Left inset of (d), optical photographs of 4-NP solution before and after the catalytic conversion by Au@rGO@cellulose.

3小结

总之，以商用纤维素纸为模板，以rGO为吸附材料，我们提出了一种高效且可扩展的方法，用于制备面积高达 3600cm2的rGO@纤维素。rGO@cellulose的rGO面积密度为7.5g/m2，在25°C 温度条件下的黄金萃取能力高达35g/m2（4660 mg/g）。此外，它还具有高选择性，可从含有 13 种金属的混合物中提取金。这种方法避免了将吸附剂从金浸出液中分离出来的高能耗过程，并能将 rGO@ 纤维素集成到连续的金萃取工艺中。

此外，这种方法的可扩展性、使用低成本、可广泛获得的材料，以及集成到连续金萃取工艺中的能力，都保证了其在金回收领域的大面积工业应用。此外，考虑到金纳米粒子的光热和催化特性，Au@rGO@纤维素被重新用于光热蒸发和催化降解4-NP。这项工作为在实际应用中使用新型 rGO 金吸附剂提供了一条可扩展的途径，展示了其在促进电子废物可持续管理和向循环经济过渡方面的广泛潜力。未来的研究应侧重于回收其他金离子，如[Au(CN)2]- 和 [Au(S2O3)2]3-，以扩大从不同废物源回收金的范围，促进金资源的可持续性。

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