Kim Sungin, Briega-Martos Valentin, Liu Shikai, Je Kwanghwi, Shi Chuqiao, Stephens Katherine Marusak, Zeltmann Steven E, Zhang Zhijing, Guzman-Soriano Rafael, Li Wenqi, Jiang Jiahong, Choi Juhyung, Negash Yafet J, Walden Franklin S, Marthe Nelson L, Wellborn Patrick S, Guo Yaofeng, Damiano John, Han Yimo, Thiede Erik H, Yang Yao
Department of Chemistry and Chemical Biology, Baker Lab, Cornell University, Ithaca, New York 14853, United States.
Department of Materials Science and Nano Engineering, Rice University, Houston, Texas 77005, United States.
J Am Chem Soc. 2025 Jul 9;147(27):23654-23671. doi: 10.1021/jacs.5c05005. Epub 2025 May 23.
/ methods have revolutionized our fundamental understanding of molecular and structural changes at solid-liquid interfaces and enabled the vision of "watching chemistry in action". transmission electron microscopy (TEM) emerges as a powerful tool to interrogate time-resolved nanoscale dynamics, which involve local electrical fields and charge transfer kinetics distinctly different from those of their bulk counterparts. Despite early reports on electrochemical or heating liquid-cell TEM, developing TEM with simultaneous electrochemical and thermal control remains a formidable challenge. Here, we developed heating and cooling electrochemical liquid-cell scanning TEM (EC-STEM). By integrating a three-electrode electrochemical circuit and an additional two-electrode thermal circuit, we can investigate heterogeneous electrochemical kinetics across a wide temperature range of -50 to 300 °C. We used Cu electrodeposition/stripping processes as a model system to demonstrate quantitative electrochemistry from -40 to 95 °C in both transient and steady states in aqueous and organic solutions, which paves the way for investigating energy materials operating in extreme climates. Machine learning-assisted quantitative 4D-STEM structural analysis in cold liquids (-40 °C) reveals a distinct two-stage growth of nanometer-scale mossy Cu nanoislands with random orientations followed by μm-scale Cu dendrites with preferential orientations. This work benchmarked electrochemistry in the three-electrode EC-STEM and systematically investigated the temperature and pH dependence of the Pt pseudoreference electrode (RE). At room temperature, the Pt pseudo-RE shows a reliable potential of 0.8 ± 0.1 V vs the standard hydrogen electrode and remains pH-independent on the reversible hydrogen electrode scale. We anticipate that heating/cooling EC-STEM will become invaluable for understanding fundamental temperature-controlled nanoscale electrochemistry and advancing renewable energy technologies (e.g., catalysts and batteries) in realistic climates.
/ 方法彻底改变了我们对固液界面分子和结构变化的基本理解，并实现了“观察化学反应过程”的愿景。透射电子显微镜（TEM）成为研究时间分辨纳米尺度动力学的强大工具，其涉及的局部电场和电荷转移动力学与体相中的明显不同。尽管早期有关于电化学或加热液体池TEM的报道，但开发同时具备电化学和热控制功能的TEM仍然是一项艰巨的挑战。在此，我们开发了加热和冷却电化学液体池扫描TEM（EC-STEM）。通过集成三电极电化学电路和额外的两电极热电路，我们可以在-50至300°C的宽温度范围内研究异相电化学动力学。我们使用铜电沉积/剥离过程作为模型系统，以证明在-40至95°C的温度范围内，在水溶液和有机溶液的瞬态和稳态下进行定量电化学研究，这为研究在极端气候条件下运行的能量材料铺平了道路。机器学习辅助的在低温液体（-40°C）中的定量4D-STEM结构分析揭示了纳米级随机取向的苔藓状铜纳米岛的独特两阶段生长，随后是微米级择优取向的铜树枝晶。这项工作为三电极EC-STEM中的电化学设定了基准，并系统地研究了铂伪参比电极（RE）的温度和pH依赖性。在室温下，铂伪参比电极相对于标准氢电极显示出0.8±0.1 V的可靠电位，并且在可逆氢电极标度上与pH无关。我们预计加热/冷却EC-STEM对于理解基本的温度控制纳米级电化学以及在实际气候条件下推进可再生能源技术（如催化剂和电池）将变得非常重要。
