The MOE Key Laboratory of Resources and Environmental System Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing, 102206, PR China.
Institute of Nuclear and New Energy Technology, Tsinghua University, Haidian District, Beijing, 100084, PR China.
Environ Pollut. 2019 Nov;254(Pt A):112854. doi: 10.1016/j.envpol.2019.07.022. Epub 2019 Jul 11.
As a useful heavy metal ion, chromium has seen its applications in various fields. While it is also a toxic contaminant in water and may cause serious threats to the environment and human health. To develop a novel material with good adsorption capacity and easy solid-liquid separation strategy was necessary and significant. In this paper, the β-cyclodextrin (β-CD) functionalized three-dimensional structured graphene foam (CDGF) was successfully synthesized with the facile and one-step hydrothermal method. The SEM, BET, XRD, FT-IR and XPS analysis were carried out and the results confirmed the successfully grafting of β-CD onto GF. The batch adsorption of Cr(VI) was also taken out and the CDGF possessed good selectivity compared with other metal ions at pH = 3. The adsorption capacity reduced gradually as the initial pH of the Cr(VI) solution grew higher, which was because the anionic species of Cr(VI) were partial to the positively charged surface of CDGF. The easy separation strategy of the CDGF was also demonstrated and the CDGF could be taken out easily with a tweezer after the adsorption of Cr(VI), which significantly simplified the separation procedure and reduced time. By comparing the FT-IR and XPD analysis results, the adsorption mechanism was explored and the hydroxyl groups on CDGF played the main role in the adsorption process. This work brings a novel material for the adsorption of Cr(VI) from water and provides an innovative direction for the easy and fast solid-liquid separation strategy in the adsorption and other application fields.
作为一种有用的重金属离子，铬在各个领域得到了广泛的应用。然而，它也是水中的一种有毒污染物，可能对环境和人类健康造成严重威胁。因此，开发一种具有良好吸附能力和易于固液分离策略的新型材料具有重要意义。本文采用简单的一步水热法成功合成了β-环糊精（β-CD）功能化三维结构石墨烯泡沫（CDGF）。通过 SEM、BET、XRD、FT-IR 和 XPS 分析对其进行了表征，结果证实了β-CD 成功接枝到 GF 上。还进行了 Cr(VI)的批量吸附实验，与其他金属离子相比，CDGF 在 pH=3 时具有更好的选择性。随着初始 Cr(VI)溶液 pH 值的升高，吸附容量逐渐降低，这是因为 Cr(VI)的阴离子物种偏向于带正电荷的 CDGF 表面。还展示了 CDGF 的易于分离策略，在吸附 Cr(VI)后，CDGF 可以用镊子轻松取出，显著简化了分离步骤并缩短了时间。通过比较 FT-IR 和 XPD 分析结果，探讨了吸附机制，发现 CDGF 上的羟基在吸附过程中起主要作用。这项工作为从水中吸附 Cr(VI)提供了一种新型材料，并为吸附和其他应用领域中的易快速固液分离策略提供了创新方向。
