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[资源] ACS Nano最新研究进展：氧化石墨烯的酸性起源、水中的不稳定性以及动力学结构模型

最新一期的ACS Nano刊发了石墨烯大牛James M. Tour课题组的最新研究进展，阐释了氧化石墨烯酸性产生的原因，并揭示了氧化石墨烯在水中不稳定的原因，最后建构了新的氧化石墨烯动力学结构模型。做石墨烯以及氧化石墨烯还原制备石墨烯的可以参考下。

The existing structural models of graphene oxide (GO) contradict each other and cannot adequately explain the acidity of its aqueous solutions. Inadequate understanding of chemical structure can lead to a misinterpretation of observed experimental phenomena. Understanding the chemistry and structure of GO should enable new functionalization protocols while explaining GO’s limitations due to its water instability. Here we propose an unconventional view of GO chemistry and develop the corresponding “dynamic structural model” (DSM). In contrast to previously proposed models, the DSM considers GO as a system, constantly changing its chemical structure due to interaction with water. Using potentiometric titration, 13C NMR, FTIR, UV–vis, X-ray photoelectron microscopy, thermogravimetric analysis, and scanning electron microscopy we show that GO does not contain any significant quantity of preexisting acidic functional groups, but gradually generates them through interaction with water. The reaction with water results in C–C bond cleavage, formation of vinylogous carboxylic acids, and the generation of protons. An electrical double layer formed at the GO interface in aqueous solutions plays an important role in the observed GO chemistry. Prolonged exposure to water gradually degrades GO flakes converting them into humic acid-like structures. The proposed DSM provides an explanation for the acidity of GO aqueous solutions and accounts for most of the known spectroscopic and experimental data.
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Graphene Oxide.jpg

[ 来自科研家族材料家族 ]

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附件 1 : GrapheneOxide.OriginofAcidity,ItsInstabilityinWater,andaNewDynamicStructuralModel-S.pdf

2012-12-15 13:20:10, 419.18 K