Faculty of Chemical Engineering, Kunming University of Science & Technology, Kunming, 650500, China.
Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming, 650500, China.
Environ Sci Pollut Res Int. 2020 Mar;27(7):7309-7317. doi: 10.1007/s11356-019-07439-2. Epub 2019 Dec 28.
The relatively low surface area and micropore volume of graphene nanosheets (GNS) limit their potential application as effective adsorbents for hydrophobic organic contaminants (HOCs). In this study, KOH etching was used to develop activated GNS (K-GNS) for adsorption of model HOCs such as naphthalene, phenol, nitrobenzene, and bisphenol A. After activation, the specific surface area (SSA) of K-GNS increased to 885 m/g, which was three times larger than that of GNS. The micropore volume of K-GNS substantially increased and the C/O ratio was doubled. Accordingly, the adsorption capacity of these HOCs on K-GNS was larger than that of pristine GNS (P-GNS) by 2-8 times. The kinetic data was fitted by the pseudo-second-order model, and the adsorption isotherms of HOCs on P-GNS and K-GNS were fitted by the Freundlich model. The desorption studies showed the K-GNS had a lower rate of release than P-GNS. The high adsorption of naphthalene, phenol, nitrobenzene, and bisphenol A on P-GNS and K-GNS is dominated by hydrophobic and π-π interactions. Additionally, the π-π EDA interaction and hydrogen bond between K-GNS and substituents cannot be ignored.
石墨烯纳米片（GNS）的比表面积和微孔体积相对较低，限制了其作为有效吸附剂吸附疏水性有机污染物（HOCs）的潜在应用。在这项研究中，使用 KOH 刻蚀法制备了用于吸附萘、苯酚、硝基苯和双酚 A 等模型 HOCs 的活化石墨烯纳米片（K-GNS）。活化后，K-GNS 的比表面积（SSA）增加到 885 m/g，是 GNS 的三倍。K-GNS 的微孔体积显著增加，C/O 比增加了一倍。因此，这些 HOCs 在 K-GNS 上的吸附容量比原始 GNS（P-GNS）大 2-8 倍。动力学数据符合准二级模型，HOCs 在 P-GNS 和 K-GNS 上的吸附等温线符合 Freundlich 模型。解吸研究表明，K-GNS 的释放率低于 P-GNS。萘、苯酚、硝基苯和双酚 A 在 P-GNS 和 K-GNS 上的高吸附主要由疏水作用和π-π相互作用主导。此外，K-GNS 与取代基之间的π-π EDA 相互作用和氢键也不容忽视。
