Wang Xin, Zhang Long
Jilin Provincial Engineering Laboratory for the Complex Utilization of Petro-resources and Biomass, School of Chemical Engineering, Changchun University of Technology Changchun Jilin 130012 P. R. China
School of Petrochemical Technology, Jilin Institute of Chemical Technology Jilin 132022 P. R. China.
RSC Adv. 2018 Dec 5;8(71):40621-40631. doi: 10.1039/c8ra07880g. eCollection 2018 Dec 4.
A novel, simple and efficient method, involving the combination of hydroxyl radicals and electrical exfoliation of graphite for the green production of high-quality graphene from graphite, was developed for the first time. The process parameters were optimized by single factor experiments; the optimal conditions were 4.0 g graphite dosage, sodium chloride solution with concentration of 5.0% (w/v), applied current strength of 10 mA, and air flow rate of 1.0 L h for 3 h. Under the optimized conditions, graphite was successfully exfoliated to graphene. SEM and TEM results revealed that the graphene product has the characteristic features of a thin-layer graphene sheet. XRD results showed that the graphene products still maintained the structure of the carbon atoms or molecules. FT-IR and Raman results indicated that the products have the characteristic peaks and absorption peaks of graphene. AFM imaging results reveal that the layer number of the graphene product obtained by this method is about 3, while the graphene products from the individual hydroxyl radical oxidation and electrical exfoliation processes were 50 and 133 layers, respectively, under the same experimental conditions. The good quality of the graphene product can be attributed to the synergistic effect between the strong oxidation of the hydroxyl radicals and electrical exfoliation. The proposed method has the advantages of simple operation, mild preparation conditions, non-utilization of aggressive reagents, recycling of the reaction medium, Thus, this method could serve as a green and efficient alternative for the production of graphene and its derivatives in industry.
首次开发了一种新颖、简单且高效的方法，该方法涉及羟基自由基与石墨的电剥离相结合，用于从石墨绿色生产高质量石墨烯。通过单因素实验对工艺参数进行了优化；最佳条件为石墨用量4.0 g、浓度为5.0%（w/v）的氯化钠溶液、施加电流强度10 mA以及空气流速1.0 L h，持续3 h。在优化条件下，石墨成功剥离为石墨烯。扫描电子显微镜（SEM）和透射电子显微镜（TEM）结果表明，石墨烯产物具有薄层石墨烯片的特征。X射线衍射（XRD）结果表明，石墨烯产物仍保持碳原子或分子的结构。傅里叶变换红外光谱（FT-IR）和拉曼光谱结果表明，产物具有石墨烯的特征峰和吸收峰。原子力显微镜（AFM）成像结果显示，通过该方法获得的石墨烯产物层数约为3层；而在相同实验条件下，单独的羟基自由基氧化和电剥离过程得到的石墨烯产物层数分别为50层和133层。石墨烯产物的良好质量可归因于羟基自由基的强氧化作用与电剥离之间的协同效应。所提出的方法具有操作简单、制备条件温和、不使用腐蚀性试剂、反应介质可循环利用等优点。因此，该方法可作为工业生产石墨烯及其衍生物的绿色高效替代方法。
