Interfacial layering of hydrocarbons on pristine graphite surfaces immersed in water
Interfacial layering of hydrocarbons on pristine graphite surfaces immersed in water
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DOI：
10.1039/d2nr04161h
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发表时间：
2022-09-20
期刊：
影响因子：
6.7
通讯作者：
Garcia, Ricardo
中科院分区：
文献类型：
--
作者：
Arvelo, Diana M.;Uhlig, Manuel R.;Garcia, Ricardo
界面水参与了涉及石墨、类石墨和2D材料界面的广泛现象。最近，一些高空间分辨率的实验已经质疑了石墨，类石墨和二维材料表面上的水化层的存在。在这里，三维原子力显微镜被应用到以下的实时和原子尺度的深度分辨率的石墨-水界面的演变。原始的石墨表面在浸入水中时显示出由0.3nm的距离分开的几个水合层的存在。这些层是短暂的。几分钟后，层间距离增加到0.45 nm。在较长的浸泡时间（类似于50分钟），我们观察到第三层的形成。0.45 nm的层间距表征了主要为烷烃类烃的分层。分子动力学计算支持实验观察。石墨上的碳氢化合物取代水分子是自发的。每当石墨-水体积暴露于空气时，就会发生这种情况。
Interfacial water participates in a wide range of phenomena involving graphite, graphite-like and 2D material interfaces. Recently, several high-spatial resolution experiments have questioned the existence of hydration layers on graphite, graphite-like and 2D material surfaces. Here, 3D AFM was applied to follow in real-time and with atomic-scale depth resolution the evolution of graphite-water interfaces. Pristine graphite surfaces upon immersion in water showed the presence of several hydration layers separated by a distance of 0.3 nm. Those layers were short-lived. After several minutes, the interlayer distance increased to 0.45 nm. At longer immersion times (similar to 50 min) we observed the formation of a third layer. An interlayer distance of 0.45 nm characterizes the layering of predominantly alkane-like hydrocarbons. Molecular dynamics calculations supported the experimental observations. The replacement of water molecules by hydrocarbons on graphite is spontaneous. It happens whenever the graphite-water volume is exposed to air.