Direct in situ characterizations of the solid–fluid interface on the nanoscale can provide profound implications for addressing bulk-scale enigmas. The advent of closed-cell environmental transmission electron microscopy (E-TEM) enables the implementation of a confined nanoscopic reactor within the high-vacuum microscope. With the encapsulations of reactant fluids and solid species under various stimuli, the whole reaction process can be observed with atomic precision and high temporal resolution. This experimental technique has been adopted widely throughout the field of nanoscience, with applications extending to the synthesis of low-dimensional materials, gas-phase catalysis, and modifications of nanomaterials, where Professor C. N. R. Rao has made substantial contributions over six decades. Here, we delve into the recent representative applications and enhancement strategies of the close gas-cell E-TEM methodology from the early development stages to the latest up-to-date ultrathin (UT) SiN_x technique. Remarkable advancements in the capabilities of multimodal data acquisition, including the quantitative electron diffraction, on-site spatiotemporal mapping of the gas molecules, and atomic-resolution real-space imaging in the gas cell E-TEM, are demonstrated. Furthermore, the integration of machine learning (ML)-assisted data acquisition and analysis is anticipated to represent the next major breakthrough, significantly expanding the applicability of gas-cell E-TEM across a wide range of research fields.

中文翻译：

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封闭式气室透射电子显微镜的进展和机遇

纳米尺度固液界面的直接原位表征可以为解决体尺度谜题提供深远的影响。闭孔环境透射电子显微镜（E-TEM）的出现使得在高真空显微镜内实现受限纳米反应器成为可能。通过在各种刺激下反应流体和固体物质的封装，可以以原子精度和高时间分辨率观察整个反应过程。这项实验技术已在整个纳米科学领域得到广泛采用，其应用范围扩展到低维材料的合成、气相催化和纳米材料的改性，CNR Rao教授在这方面做出了六十年来的重大贡献。在这里，我们深入研究了封闭气室 E-TEM 方法的最新代表性应用和增强策略，从早期开发阶段到最新的超薄 (UT) SiN _x技术。展示了多模态数据采集能力的显着进步，包括定量电子衍射、气体分子的现场时空测绘以及气室 E-TEM 中的原子分辨率实空间成像。此外，机器学习 (ML) 辅助数据采集和分析的集成预计将代表下一个重大突破，显着扩展气室 E-TEM 在广泛研究领域的适用性。