Chemically homogeneous and thermally reversible oxidation of epitaxial graphene
Chemically homogeneous and thermally reversible oxidation of epitaxial graphene
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DOI：
10.1038/nchem.1269
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发表时间：
2012-04-01
期刊：
影响因子：
21.8
通讯作者：
Hersam, Mark C.
中科院分区：
文献类型：
--
作者：
Hossain, Md. Zakir;Johns, James E.;Hersam, Mark C.
凭借其出色的电荷迁移率，石墨烯在下一代电子产品中的应用前景广阔。为了调整其性质和界面特性，石墨烯的化学功能化正在积极进行。通过Hummers方法氧化石墨烯在当前研究中使用最广泛，尽管所得氧化石墨烯的化学不均匀性和不可逆性损害了其在高性能设备中的使用。在这里，我们提出了一种替代的方法，用于氧化外延石墨烯，在真空中使用原子氧。原子分辨率表征与扫描隧道显微镜定量比较密度泛函理论，表明超高真空氧化均匀的环氧官能化的结果。此外，使用扫描隧道显微镜和光谱技术，这种氧化在低至260摄氏度的温度下是完全可逆的。通过这种方式，超高真空氧化克服了Hummers方法氧化石墨烯的局限性，从而为化学功能化石墨烯的研究和应用创造了新的机会。
With its exceptional charge mobility, graphene holds great promise for applications in next-generation electronics. In an effort to tailor its properties and interfacial characteristics, the chemical functionalization of graphene is being actively pursued. The oxidation of graphene via the Hummers method is most widely used in current studies, although the chemical inhomogeneity and irreversibility of the resulting graphene oxide compromises its use in high-performance devices. Here, we present an alternative approach for oxidizing epitaxial graphene using atomic oxygen in ultrahigh vacuum. Atomic-resolution characterization with scanning tunnelling microscopy is quantitatively compared to density functional theory, showing that ultrahigh-vacuum oxidization results in uniform epoxy functionalization. Furthermore, this oxidation is shown to be fully reversible at temperatures as low as 260 degrees C using scanning tunnelling microscopy and spectroscopic techniques. In this manner, ultrahigh-vacuum oxidation overcomes the limitations of Hummers-method graphene oxide, thus creating new opportunities for the study and application of chemically functionalized graphene.