Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, 3, Acad. Lavrentiev prosp., Novosibirsk 630090, Russia.
Chem Asian J. 2013 Sep;8(9):2015-22. doi: 10.1002/asia.201300401. Epub 2013 May 31.
We have fluorinated few-layer graphene (FLG) by using a low-temperature fluorination route with gaseous ClF3. The treatment process resulted in a new graphene derivative with a finite approximate composition of C2F. TEM studies showed that the product consisted of thin transparent sheets with no more than 10 fluorographene layers stacked together. Spectroscopic methods revealed a predominantly covalent nature of the C-F bonds in the as-synthesized product and we found no evidence for the existence of so-called "semi-ionic" C-F bonds, as observed in bulk C(x)F. In contrast to the case of graphite and typical (thick) expanded graphites, fluorination of FLG did not lead to the intercalation of ClF3 molecules, owing to the lack of a 3D layered structure. The approximate "critical" number of graphene layers that were necessary to form a phase of intercalated compound was estimated to be more than 12, thus providing a "chemical proof" of the difference between the properties of few-layered graphenes and bulk graphites. Fluorographene C2F was successfully delaminated into thinner layers in organic solvents, which is an important property for its integration into electronic devices, nanohybrids, etc.
我们使用低温氟化法，以气态 ClF3 对少层氟化石墨烯（FLG）进行了氟化处理。该处理过程得到了一种新的石墨烯衍生物，其近似组成有限，约为 C2F。TEM 研究表明，产物由厚度不超过 10 层的透明薄片组成，这些薄片堆叠在一起。光谱方法表明，在合成产物中 C-F 键主要具有共价性质，我们没有发现所谓的“半离子”C-F 键的存在证据，而在大块 C(x)F 中观察到了这种键。与石墨和典型（厚）膨胀石墨的情况相反，由于缺乏 3D 层状结构，FLG 的氟化并没有导致 ClF3 分子的插层。形成插层化合物相所需的石墨烯层的近似“临界”数量估计超过 12，从而为少层石墨烯和块状石墨之间的性质差异提供了“化学证明”。氟化石墨烯 C2F 在有机溶剂中成功地分层成更薄的层，这对于将其集成到电子设备、纳米杂化物等中是一个重要的性质。
