Wang Yufei, Garcia-Carrillo Roberto, Ren Hang
Department of Chemistry, The University of Texas at Austin Austin TX 78712 USA
Center for Electrochemistry, The University of Texas at Austin Austin TX 78712 USA.
Chem Sci. 2024 Dec 16;16(3):1447-1454. doi: 10.1039/d4sc05954a. eCollection 2025 Jan 15.
Electrochemical metal dissolution reaction is a fundamental process in various critical technologies, including metal anode batteries and nanofabrication. However, experimentally revealing the kinetics and dynamics of active sites of metal dissolution reactions is challenging. Herein, we investigate metal dissolution on near-perfect single-crystal surfaces of Ag within regions of a few hundred nanometers isolated by scanning electrochemical cell microscopy (SECCM). Potential oscillation is observed under constant current conditions for dissolution. The one-to-one correspondence between the dissolution charge and the geometry of the dissolution pit from colocalized imaging allows ambiguous correlation, which suggests that each oscillation cycle corresponds to the dissolution of one atomic layer. The oscillation behavior is further explained in a kinetic model, which reveals that the oscillation comes from the dynamic evolution of the number of different active sites as the dissolution progresses on each atomic layer. In addition to the fundamental interest, the ability to observe layer-by-layer dissolution in electrochemical measurements suggests a potential pathway for developing electrochemical atomic layer etching for fabricating structures and devices with atomic precision.
电化学金属溶解反应是包括金属阳极电池和纳米制造在内的各种关键技术中的一个基本过程。然而，通过实验揭示金属溶解反应活性位点的动力学和动力学是具有挑战性的。在此，我们利用扫描电化学池显微镜（SECCM）在几百纳米区域内研究了银的近完美单晶表面上的金属溶解。在恒定电流溶解条件下观察到电位振荡。通过共定位成像得到的溶解电荷与溶解坑几何形状之间的一一对应关系允许进行明确的关联，这表明每个振荡周期对应于一个原子层的溶解。在动力学模型中进一步解释了振荡行为，该模型表明振荡来自于随着溶解在每个原子层上进行，不同活性位点数量的动态演变。除了基本的研究兴趣之外，在电化学测量中观察到逐层溶解的能力为开发用于制造具有原子精度的结构和器件的电化学原子层蚀刻提供了一条潜在途径。
