In Situ Visual Observation of Surface Energy-Controlled Heterogeneous Nucleation of Metal Nanocrystals.

ABSTRACT

Electrochemical growth of metal nanocrystals is pivotal for material synthesis, processing, and resource recovery. Understanding the heterogeneous interface between electrolyte and electrode is crucial for nanocrystal nucleation, but the influence of this interaction is still poorly understood. This study employs advanced in situ measurements to investigate the heterogeneous nucleation of metals on solid surfaces. By observing the copper nanocrystal electrodeposition, an interphase interaction-induced nucleation mechanism highly dependent on substrate surface energy is uncovered. It shows that a high-energy (HE) electrode tended to form a polycrystalline structure, while a low-energy (LE) electrode induced a monocrystalline structure. Raman and electrochemical characterizations confirmed that HE interface enhances the interphase interaction, reducing the nucleation barrier for the sturdy nanostructures. This leads to a 30.92-52.21% reduction in the crystal layer thickness and a 19.18-31.78% increase in the charge transfer capability, promoting the formation of a uniform and compact film. The structural compactness of the early nucleated crystals enhances the deposit stability for long-duration electrodeposition. This research not only inspires comprehension of physicochemical processes correlated with heterogeneous nucleation, but also paves a new avenue for high-quality synthesis and efficient recovery of metallic nanomaterials.