On the Nature of Defects in Liquid-Phase Exfoliated Graphene
On the Nature of Defects in Liquid-Phase Exfoliated Graphene
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DOI：
10.1021/jp501930a
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发表时间：
2014-07-17
影响因子：
3.7
通讯作者：
Foa Torres, L. E. F.
中科院分区：
文献类型：
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作者：
Bracamonte, M. V.;Lacconi, G. I.;Foa Torres, L. E. F.
液相剥离是大规模生产多层石墨烯分散体最有前途的途径之一。这些分散体可用于涂料、复合材料或油漆，据信含有无无序石墨烯多层。在这里，我们讨论了通过在n -甲基-2-吡咯烷酮中对石墨粉末进行液相剥离得到的样品中缺陷的性质。我们的拉曼光谱数据挑战了这些多层材料没有体缺陷的假设，揭示了缺陷的定位在很大程度上取决于超声时间。在较短的超声时间内，缺陷主要位于层边缘，但在超声时间超过2小时时，缺陷会在整体中积聚。这一知识可能有助于设计出更好的策略来实现高质量的石墨烯分散体。
Liquid-phase exfoliation is one of the most promising routes for large-scale production of multilayer graphene dispersions. These dispersions, which may be used in coatings, composites, or paints, are believed to contain disorder-free graphene multilayers. Here, we address the nature of defects in such samples obtained by liquid-phase exfoliation of graphite powder in N-methyl-2-pyrrolidone. Our Raman spectroscopy data challenge the assumption that these multilayers are free of bulk defects, revealing that defect localization strongly depends on the sonication time. For short ultrasound times, defects are located mainly at the layer edges but they turn out to build up in the bulk for ultrasonic times above 2 h. This knowledge may help to devise better strategies to achieve high-quality graphene dispersions.