Abstract Graphene oxide (GO) is an interesting material that has the potential for a wide range of applications. Critical for these applications are the type of oxygen bond and its spatial distribution on the individual GO sheets. This distribution is not yet well understood. Few techniques offer a resolution high enough to unambiguously identify oxygen configuration. We used a new, label free spectroscopic technique to map oxygen bonding on GO, with spatial resolution of nanometres and high chemical specificity. AFM-IR, atomic force microscopy coupled with infrared spectroscopy, overcomes conventional IR diffraction limits, producing IR spectra from specific points as well as chemical maps that are coupled to topography. We have directly observed oxygen bonding preferentially on areas where graphene is folded, in discrete domains and on edges of GO. From these observations, we propose an updated structural model for GO, with C O on its edge and plane, which confirms parts of earlier proposed models. The results have interesting implications. Determining atomic position and configuration from precise imaging offers the possibility to link nanoscale structure and composition with material function, paving the way for targeted tethering of ions, polymers and biomaterials.

中文翻译：

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直接观察单个氧化石墨烯片上的氧构型

摘要 氧化石墨烯（GO）是一种有趣的材料，具有广泛的应用潜力。这些应用的关键是氧键的类型及其在单个 GO 片上的空间分布。这种分布还不是很清楚。很少有技术提供足够高的分辨率来明确识别氧构型。我们使用了一种新的无标记光谱技术来绘制 GO 上的氧键，具有纳米级的空间分辨率和高化学特异性。AFM-IR，原子力显微镜与红外光谱相结合，克服了传统的红外衍射极限，从特定点产生红外光谱以及与地形耦合的化学图。我们直接观察到氧键优先出现在石墨烯折叠的区域，在离散域和 GO 的边缘。根据这些观察，我们提出了一个更新的 GO 结构模型，在其边缘和平面上有 CO，这证实了早期提出的模型的一部分。结果具有有趣的意义。通过精确成像确定原子位置和配置提供了将纳米级结构和成分与材料功能联系起来的可能性，为离子、聚合物和生物材料的靶向束缚铺平了道路。