Guo Xitao, Li Jinhuan, Yu Yuanfang, Zafar Amina, Ni Zhenhua
School of Mechanical and Electronic Engineering, East China University of Technology, Nanchang, 330013, People's Republic of China.
Nanotechnology. 2019 Jul 19;30(29):295704. doi: 10.1088/1361-6528/ab1780. Epub 2019 Apr 9.
We present a simple, but rapid and accurate approach to identify the layer number of graphene oxide (GO) by using its thermally enhanced optical contrast via vacuum heating. As expected, changes have been observed both in the thicknesses and chemical structures of the material upon the thermal treatment, which can be attributed to the reduction of the amount of intercalated water and oxygen content. This results in the increase of refractive index and absorption coefficient approaching the values for intrinsic graphene. Finally, we achieve an almost complete recovery of optical contrast of GO compared with the one of graphene. The method would be made suitable for the thickness identification of mass-produced GO since it can greatly facilitate sample evaluation and manipulation, and provide immediate feedback to improve synthesis and processing strategies.
我们提出了一种简单、快速且准确的方法，通过真空加热利用氧化石墨烯（GO）热增强的光学对比度来识别其层数。正如预期的那样，在热处理后观察到了材料厚度和化学结构的变化，这可归因于插层水含量和氧含量的减少。这导致折射率和吸收系数增加，接近本征石墨烯的值。最后，与石墨烯相比，我们实现了氧化石墨烯光学对比度的几乎完全恢复。该方法适用于大规模生产的氧化石墨烯的厚度识别，因为它可以极大地促进样品评估和操作，并提供即时反馈以改进合成和加工策略。
