Tene Talia, Guevara Marco, Valarezo Andrea, Salguero Orlando, Arias Arias Fabian, Arias Melvin, Scarcello Andrea, Caputi Lorenzo S, Vacacela Gomez Cristian
Grupo de Fisicoquímica de Materiales, Universidad Técnica Particular de Loja, Loja EC-110160, Ecuador.
CompNano, School of Physical Sciences and Nanotechnology, Yachay Tech University, Urcuquí EC-100119, Ecuador.
Nanomaterials (Basel). 2021 Apr 19;11(4):1035. doi: 10.3390/nano11041035.
Graphene oxide (GO) exhibits different properties from those found in free-standing graphene, which mainly depend on the type of defects induced by the preparation method and post-processing. Although defects in graphene oxide are widely studied, we report the effect of drying time in GO and how this modifies the presence or absence of edge-, basal-, and sp-type defects. The effect of drying time is evaluated by Raman spectroscopy, UV-visible spectroscopy, and transmission electron microscopy (TEM). The traditional D, G, and 2D peaks are observed together with other less intense peaks called the D', D*, D**, D+G, and G+D. Remarkably, the D* peak is activated/deactivated as a direct consequence of drying time. Furthermore, the broad region of the 2D peak is discussed as a function of its deconvoluted 2D, 2D, and D+G bands. The main peak in UV-visible absorption spectra undergoes a redshift as drying time increases. Finally, TEM measurements demonstrate the stacking of exfoliated GO sheets as the intercalated (water) molecules are removed.
氧化石墨烯（GO）具有与独立存在的石墨烯不同的性质，这主要取决于制备方法和后处理所诱导的缺陷类型。尽管氧化石墨烯中的缺陷已得到广泛研究，但我们报告了干燥时间对氧化石墨烯的影响以及这如何改变边缘、基面和sp型缺陷的存在与否。通过拉曼光谱、紫外可见光谱和透射电子显微镜（TEM）评估干燥时间的影响。观察到传统的D、G和2D峰以及其他强度较低的峰，即D'、D*、D**、D+G和G+D峰。值得注意的是，D*峰作为干燥时间的直接结果被激活/失活。此外，讨论了2D峰的宽区域与其解卷积后的2D、2D和D+G带的函数关系。随着干燥时间的增加，紫外可见吸收光谱中的主峰发生红移。最后，TEM测量表明，随着插层（水）分子的去除，剥落的氧化石墨烯片层发生堆叠。
