Regional Centre of Advanced Technologies and Materials, Faculty of Science, Department of Physical Chemistry, Palacký University, Olomouc, 77146, Czech Republic.
Division of Chemistry & Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore.
Small. 2015 Aug;11(31):3790-6. doi: 10.1002/smll.201500364. Epub 2015 May 4.
Halogen functionalization of graphene is an important branch of graphene research as it provides opportunities to tailor the band gap and catalytic properties of graphene. Monovalent C-X bond obviates pitfalls of functionalization with atoms of groups 13, 15, and 16, which can introduce various poorly defined groups. Here, the preparation of functionalized graphene containing both fluorine and chlorine atoms is shown. The starting material, fluorographite, undergoes a reaction with dichlorocarbene to provide dichlorocarbene-functionalized fluorographene (DCC-FG). The material is characterized by X-ray photoelectron spectroscopy, Raman spectroscopy, and high-resolution transmission electron microscopy with X-ray dispersive spectroscopy. It is found that the chlorine atoms in DCC-FG are distributed homogeneously over the entire area of the fluorographene sheet. Further density functional theory calculations show that the mechanism of dichlorocarbene attack on fluorographene sheet is a two-step process. Dichlorocarbene detaches fluorine atoms from fluorographene sheet and subsequently adds to the newly formed sp(2) carbons. Halogenated graphene consisting of two (or eventually three) types of halogen atoms is envisioned to find its way as new graphene materials with tailored properties.
石墨烯的卤化功能化是石墨烯研究的一个重要分支，因为它为调整石墨烯的能带隙和催化性能提供了机会。一价 C-X 键消除了用第 13、15 和 16 族原子进行功能化的陷阱，这些原子可能会引入各种定义不明确的基团。本文展示了含有氟和氯原子的功能化石墨烯的制备。起始材料氟化石墨与二氯卡宾反应，得到二氯卡宾功能化的氟化石墨（DCC-FG）。该材料通过 X 射线光电子能谱、拉曼光谱和高分辨率透射电子显微镜与 X 射线分散光谱进行了表征。结果表明，DCC-FG 中的氯原子在整个氟化石墨片的整个区域均匀分布。进一步的密度泛函理论计算表明，二氯卡宾对氟化石墨片的攻击机制是一个两步过程。二氯卡宾从氟化石墨片上脱离氟原子，然后添加到新形成的 sp(2)碳上。预计由两种（或最终三种）类型卤素原子组成的卤化石墨烯将作为具有定制性能的新型石墨烯材料得到应用。
