Real-time TEM observations of ice formation in graphene liquid cell
Real-time TEM observations of ice formation in graphene liquid cell
复制标题
石墨烯液体电池中冰形成的实时 TEM 观察
DOI：
10.1039/d3nr00097d
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发表时间：
2023
期刊：
影响因子：
6.7
通讯作者：
Shahbazian-Yassar, Reza
中科院分区：
文献类型：
--
作者：
Phakatkar, Abhijit H.;Megaridis, Constantine M.;Shokuhfar, Tolou;Shahbazian-Yassar, Reza
在纳米尺度上研究冰的成核和生长在地质和大气科学中具有极其重要的意义。然而，现有的透射式电子显微镜(TEM)方法在直接成像冰形成方面并不成功。在这里，我们展示了在石墨烯液体电池(GLC)中包裹水的自由基清除剂--如二氧化钛--如何有助于在低温下观察到冰核现象。原子分辨率成像揭示了立方冰相晶体在低温下靠近二氧化钛-水纳米界面的成核和生长。有趣的是，非均质成核和均一成核的冰晶都有这种立方相。与块体液体中的晶体(均匀成核)相比，冰晶核在二氧化钛-水纳米界面上更稳定，这表明纳米二氧化钛具有清除自由基的能力，减少了电子束的副产物。目前的工作表明，在GLC-TEM中使用自由基清除剂对揭示冰成核和生长动力学事件的纳米尺度路径具有很大的前景。
The study of ice nucleation and growth at the nanoscale is of utmost importance in geological and atmospheric sciences. However, existing transmission electron microscopy (TEM) approaches have been unsuccessful in imaging ice formation directly. Herein, we demonstrate how radical scavengers – such as TiO2 – encased with water in graphene liquid cells (GLCs) facilitate the observation of ice nucleation phenomena at low temperatures. Atomic-resolution imaging reveals the nucleation and growth of cubic ice-phase crystals at close proximity to TiO2–water nanointerfaces at low temperatures. Interestingly, both heterogeneously and homogeneously nucleated ice crystals exhibited this cubic phase. Ice crystal nuclei were observed to be more stable at the TiO2–water nanointerface, as compared with crystals in the bulk liquid (homogeneous nucleation), suggesting the radical scavenging efficacy of TiO2 nanoparticles mitigating the electron beam by-products. The present work demonstrates that the use of radical scavengers in GLC TEM shows great promise towards unveiling the nanoscale pathways for ice nucleation and growth dynamic events.