Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Beauchef 850, Santiago, Chile.
Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, S. Livingstone 1007, Santiago, Chile.
J Colloid Interface Sci. 2018 Aug 15;524:219-226. doi: 10.1016/j.jcis.2018.04.030. Epub 2018 Apr 6.
The fluorination of two types of graphene oxides conducted by an easy and scalable deoxyfluorination reaction is reported. This reaction was carried out using diethylaminodifluorosulfinium tetrafluoroborate, a stable compound and an efficient reagent for replacing oxygenated functional groups of graphene oxide by fluoride. The graphene oxide produced by the Hummers' method (GOH) showed lower reactivity than that produced by the Brodie's method (GOB). X-ray photoelectron spectroscopy indicated that the highest fluorination degree achieved was 4.7 at.% when GOB was used, and the CF character corresponds to semi-ionic bonds. Additionally, a partial reduction of GO was concomitant with the functionalization reaction. The deoxyfluorination reaction changed the crystalline structure of GO, favoring the reconstruction of Csp structure of the graphene lattice and reducing the number of stacked layers. The fluorination led to the modification of the electronic band structure of this material, increasing the band gap from 2.05 eV for GOB to 3.88 eV for fluorinated GOB, while for GOH the low flurionation led to a slight increase of the band gap, from 3.48 eV to 3.57 eV.
本文报道了通过一种简单且可扩展的脱氧氟化反应对两种类型的氧化石墨烯进行氟化。该反应使用二乙氨基二氟磺酰氟四氟硼酸盐进行，这是一种稳定的化合物，也是一种有效试剂，可将氧化石墨烯含氧官能团用氟取代。通过 Hummers 法（GOH）制备的氧化石墨烯的反应活性低于通过 Brodie 法（GOB）制备的氧化石墨烯。X 射线光电子能谱表明，当使用 GOB 时，最高氟取代度为 4.7 at.%，CF 特征对应于半离子键。此外，GO 的部分还原伴随着官能化反应。脱氧氟化反应改变了 GO 的晶体结构，有利于石墨烯晶格 Csp 结构的重构，减少了堆叠层数。氟化导致该材料的电子能带结构发生变化，使 GOB 的能带隙从 2.05 eV 增加到氟化 GOB 的 3.88 eV，而对于 GOH，低氟化导致能带隙略有增加，从 3.48 eV 增加到 3.57 eV。
