Karnis Ioannis, Krasanakis Fanourios, Sygellou Labrini, Rissanou Anastassia N, Karatasos Konstantinos, Chrissopoulou Kiriaki
Institute of Electronic Structure and Laser, Foundation for Research and Technology-Hellas, P.O. Box 1527, Heraklion Crete 711 10, Greece.
Department of Chemistry, University of Crete, Heraklion Crete, Greece.
Phys Chem Chem Phys. 2024 Mar 27;26(13):10054-10068. doi: 10.1039/d3cp05268k.
In this work, we employ a fast and less toxic modified Hummers' method to develop graphene oxide (GO) with varying degrees of oxidation and investigate the effect of the latter on the structure and the thermal properties of the synthesized materials. Two different key parameters, the time of the oxidation reaction and the mass of the oxidation agent, were systematically altered in order to fine tune the oxidation degree. All graphene oxides were characterized by a plethora of experimental techniques, like X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) as well as infrared spectroscopy (IR) and X-ray photoelectron spectroscopy (XPS) for their structural, thermal and chemical identification. The results revealed that for a certain amount of oxidant, the time does not affect the final degree of oxidation of the materials, at least for the examined reaction times, because very similar structural patterns and thermal properties were obtained. At the same time, the oxygen-containing functional groups were found very similar. On the other hand, the degree of oxidation was found highly dependent on the mass of the oxidizing agent. XRD analysis showed a systematic increase of the interlayer distance of the synthesized GOs with the increase of the oxidant mass, whereas both the enthalpy of reduction and the % weight loss were increased. Moreover, XPS measurements provided a quantitative evaluation of the amount of carbon and oxygen in the materials; the increase of the oxidant mass led to a decrease of the total carbon content with the concurrent increase of the total oxygen amount.
在这项工作中，我们采用一种快速且毒性较小的改良Hummers法来制备具有不同氧化程度的氧化石墨烯（GO），并研究其对合成材料的结构和热性能的影响。为了微调氧化程度，系统地改变了两个不同的关键参数，即氧化反应时间和氧化剂质量。所有氧化石墨烯均通过大量实验技术进行表征，如用于结构、热和化学鉴定的X射线衍射（XRD）、差示扫描量热法（DSC）、热重分析（TGA）以及红外光谱（IR）和X射线光电子能谱（XPS）。结果表明，对于一定量的氧化剂，时间至少在所研究的反应时间范围内不影响材料的最终氧化程度，因为获得了非常相似的结构模式和热性能。同时，发现含氧官能团非常相似。另一方面，发现氧化程度高度依赖于氧化剂的质量。XRD分析表明，随着氧化剂质量的增加，合成的氧化石墨烯的层间距系统性增加，而还原焓和失重百分比均增加。此外，XPS测量提供了对材料中碳和氧含量的定量评估；氧化剂质量的增加导致总碳含量降低，同时总氧量增加。
