Nucleation Site Distribution Probed by Phase-Enhanced Environmental Scanning Electron Microscopy

Nucleation site distribution is ubiquitous in many natural and industrial processes, such as liquid-to-vapor phase change, gas-evolving reactions, and solid-state material growth. However, a comprehensive understanding of nucleation site distribution remains elusive. These limitations are due to the challenge of probing micro/nanoscopic nucleation sites and inadequate statistical interpretation of the nucleation process. Here we report direct experimental observation of nucleation site distribution in droplet condensation using phase-enhanced environmental scanning electron microscopy We also use statistical theory to demonstrate that the population of nucleation sites is governed by the Poisson distribution, whereas the nearest-neighbor distance follows the Rayleigh distribution instead of the commonly used Poisson distribution. We further show the broad applicability of these insights into nucleation site distribution to hydrogen-evolving reactions and chemical vapor deposition. Our platform, combining precise characterization and theory, advances the fundamental understanding of nucleation phenomena and guides designs from materials to devices.