Unveiling Corrosion Pathways of Sn Nanocrystals through High-Resolution Liquid Cell Electron Microscopy
Xinxing Peng, Junyi Shangguan, Qiubo Zhang, Matthew R. Hauwiller, Haobo Yu, Yifan Nie, Karen C. Bustillo, A. Paul Alivisatos, Mark Asta, Haimei Zheng
Abstract
High Resolution Image Download MS PowerPoint Slide Unveiling materials’ corrosion pathways is significant for understanding the corrosion mechanisms and designing corrosion-resistant materials. Here, we investigate the corrosion behavior of Sn@Ni 3 Sn 4 and Sn nanocrystals in an aqueous solution in real time by using high-resolution liquid cell transmission electron microscopy. Our direct observation reveals an unprecedented level of detail on the corrosion of Sn metal with/without a coating of Ni 3 Sn 4 at the nanometric and atomic levels. The Sn@Ni 3 Sn 4 nanocrystals exhibit “pitting corrosion”, which is initiated at the defect sites in the Ni 3 Sn 4 protective layer. The early stage isotropic etching transforms into facet-dependent etching, resulting in a cavity terminated with low-index facets. The Sn nanocrystals under fast etching kinetics show uniform corrosion, and smooth surfaces are obtained. Sn nanocrystals show “creeping-like” etching behavior and rough surfaces. This study provides critical insights into the impacts of coating, defects, and ion diffusion on corrosion kinetics and the resulting morphologies.