Beijing Key Laboratory of Environmental Science and Engineering, School of Materials Science & Engineering, Beijing Institute of Technology, Beijing, 100081, China.
Beijing Key Laboratory of Environmental Science and Engineering, School of Materials Science & Engineering, Beijing Institute of Technology, Beijing, 100081, China.
Chemosphere. 2020 Jan;238:124638. doi: 10.1016/j.chemosphere.2019.124638. Epub 2019 Aug 22.
In this study, we reported on the recycling of carbon materials from spent commercial supercapacitors and its application as low-cost adsorbent for high-efficiency removal of Ag(I) and Cr(VI) ions from aqueous solutions. Adsorption kinetics and isotherms, and effects of initial pH were carried out to investigate the adsorption performance of the recycled supercapacitor activated carbon (RSAC), whereas a series of characterizations such as SEM, EDX, BET, XPS, XRD and FTIR were employed to detailedly analyse the adsorption mechanism. The RSAC showed maximal adsorption capacity for Ag(I) and Cr(VI) of 104.0 and 96.3 mg g, respectively, with adsorbent dosage of 2 g L and initial ions concentration of ∼2000 mg L at room temperature (23 ± 1 °C), and the adsorption was rapid and influenced by the initial pH value. The outstanding adsorption performance of RSAC was attributed to the high specific surface area (1403 m g) and abundant multifarious oxygenic groups which could participate in the electrostatic attraction and reduction reaction of Ag(I) and Cr(VI) during the adsorption process. Furthermore, the predominate species of the adsorbed toxic Ag(I) and Cr(VI) on the surface of RSAC was metallic silver particle (about 2 μm) and harmless Cr(III), respectively, thus it was possible for further recycling and disposal.
在这项研究中，我们报告了从废旧商用超级电容器中回收碳材料，并将其应用于高效去除水溶液中 Ag(I) 和 Cr(VI) 离子的低成本吸附剂。我们进行了吸附动力学和等温线以及初始 pH 值的影响研究，以考察回收超级电容器活性炭（RSAC）的吸附性能，同时采用 SEM、EDX、BET、XPS、XRD 和 FTIR 等一系列表征方法详细分析了吸附机理。RSAC 在室温（23±1°C）下，以 2 g·L 的吸附剂用量和初始离子浓度约为 2000 mg·L 时，对 Ag(I) 和 Cr(VI) 的最大吸附容量分别为 104.0 和 96.3 mg·g，吸附速度快，且受初始 pH 值影响。RSAC 具有出色的吸附性能，这归因于其高比表面积（1403 m²·g）和丰富的多样含氧基团，这些基团可在吸附过程中参与 Ag(I) 和 Cr(VI) 的静电吸引和还原反应。此外，RSAC 表面吸附的有毒 Ag(I) 和 Cr(VI) 的主要物种分别是金属银颗粒（约 2 μm）和无害的 Cr(III)，因此可进一步回收和处理。
