Farag Ahmed A, Gafar Afif Aboubakr, Salih Said A, Altalhi Amal A, Mohamed Eslam A, Mohamed Gehad G
Egyptian Petroleum Research Institute (EPRI), 11727Cairo, Egypt.
Chemistry Department, Faculty of Science, Cairo University, 12613Giza, Egypt.
ACS Omega. 2022 Oct 20;7(43):38347-38360. doi: 10.1021/acsomega.2c03150. eCollection 2022 Nov 1.
In this study, graphene oxide (GO) was functionalized with 3,5-diaminobenzoic acid (DABA) by a one-step method to produce functionalized graphene oxide (FGO). FGO is a new type of absorbent crystalline substance that has a high surface area and a large porosity site as well as a large number of dentate functional groups which lead to enhanced adsorption performance for heavy metal ions. The adsorption efficiency of FGO for Pb and Al metal ions was extra satisfactory when compared with GO due to the ease of design and the homogeneous structure of FGO. The structure of synthesized GO and FGO was confirmed by different techniques such as FTIR, XRD, TGA, BET nitrogen adsorption-desorption methods, and TEM analyses. The mass of utilized adsorbents, the pH of the medium, the concentration of ionic species in the medium, temperature, and process time were all investigated as variables in the adsorbent procedure. The experimental data recorded that the maximum adsorption efficiency of the 0.5 g/L FGO composite was 99.7 and 99.8% for Pb and Al metal ions, respectively, while in the case of using GO, the maximum adsorption efficiency was 92.6 and 91.9% at ambient temperature in a semineutral medium at pH 6 after 4 h. The adsorption results were in good conformity with the Freundlich model and pseudo-second-order kinetics for Pb and Al metal ions. Also, the reusability study indicates that FGO can be used repeatedly at least for five cycles with a slight significant loss in its efficiency.
在本研究中，采用一步法用3,5 - 二氨基苯甲酸（DABA）对氧化石墨烯（GO）进行功能化处理，以制备功能化氧化石墨烯（FGO）。FGO是一种新型吸附性晶体物质，具有高比表面积、大量孔隙位点以及大量齿状官能团，这些导致其对重金属离子的吸附性能增强。与GO相比，FGO对铅和铝金属离子的吸附效率格外令人满意，这归因于FGO易于设计且结构均匀。通过傅里叶变换红外光谱（FTIR）、X射线衍射（XRD）、热重分析（TGA）、BET氮吸附 - 脱附方法以及透射电子显微镜（TEM）分析等不同技术对合成的GO和FGO的结构进行了确认。在吸附过程中，研究了所用吸附剂的质量、介质的pH值、介质中离子物种的浓度、温度和处理时间等变量。实验数据表明，0.5 g/L的FGO复合材料对铅和铝金属离子的最大吸附效率分别为99.7%和99.8%，而在使用GO的情况下，在pH值为6的半中性介质中，室温下4小时后最大吸附效率分别为92.6%和91.9%。吸附结果与铅和铝金属离子的Freundlich模型及准二级动力学模型高度吻合。此外，可重复使用性研究表明，FGO至少可以重复使用五个循环，其效率仅有轻微的显著损失。
