Laterally Selective Oxidation of Large-Scale Graphene with Atomic Oxygen
Laterally Selective Oxidation of Large-Scale Graphene with Atomic Oxygen
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DOI：
10.1021/acs.jpcc.7b07840
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发表时间：
2017-12-21
影响因子：
3.7
通讯作者：
Yashina, Lada V.
中科院分区：
文献类型：
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作者：
Kapitanova, Olesya O.;Kataev, Elmar Yu.;Yashina, Lada V.
使用X射线光电子显微镜，我们发现，通过原子氧氧化通常具有双层岛的Cu箔上的商业大规模石墨烯进行特定结构的形成：虽然相对移动的环氧基团在单层石墨烯的表面上均匀地产生，但它们的浓度对于双层岛显著较低。更氧化的物质如羰基和内酯优选位于这些双层岛的中心。在我们的例子中，这种结构随机分布在表面上，平均密度约为3 × 106 cm（-2）。使用一套先进的光谱显微镜仪器，包括拉曼显微镜，X射线光电子能谱（mu-XPS），俄歇电子能谱（nano-AES），角分辨光电子能谱（mu-ARPES），我们发现，中心的双层岛的第二层成核具有高的缺陷浓度，并作为深氧化的活性位点。这一信息在开发基于石墨烯/氧化石墨烯异质结的电子学和光电子学横向异质结构中可能是有用的
Using X-ray photoemission microscopy, we discovered that oxidation of commercial large-scale graphene on Cu foil, which typically has bilayer islands, by atomic oxygen proceeds with the formation of the specific structures: though relatively mobile epoxy groups are generated uniformly across the surface of single-layer graphene, their concentration is significantly lower for bilayer islands. More oxidized species like carbonyl and lactones are preferably located at the centers of these bilayer islands. Such structures are randomly distributed over the surface with a mean density of about 3 x 106 cm(-2) in our case. Using a set of advanced spectromicroscopy instruments including Raman microscopy, X-ray photoelectron spectroscopy (mu-XPS), Auger electron spectroscopy (nano-AES), and angle-resolved photoelectron spectroscopy (mu-ARPES), we found that the centers of the bilayer islands where the second layer nucleates have a high defect concentration and serve as the active sites for deep oxidation. This information can be potentially useful in developing lateral heterostructures for electronics and optoelectronics based on graphene/graphene oxide heterojunctions