Identification of a Critical Intermediate in Galvanic Exchange Reactions by Single‐Nanoparticle‐Resolved Kinetics

• DOI: 10.1002/anie.201309307
• Publication Date: 2014-02-07T11:36:49Z
• Authors: Jeremy G. Smith; Qing Yang; Prashant K. Jain
• Keywords: Galvanic cell; Void (composites); Nanocrystalline material; Nanocages; Nanoshell

Abstract The realization of common materials transformations in nanocrystalline systems is fostering the development novel nanostructures and allowing a deep look into atomistic mechanisms involved. Galvanic corrosion one such transformation. We studied galvanic replacement within individual metal nanoparticles by using combination plasmonic spectroscopy scanning transmission electron microscopy. Single‐nanoparticle reaction trajectories showed that Ag nanoparticle exposed to Au 3+ makes an abrupt transition nanocage structure. limited critical structural event, which we identified microscopy comprise formation nanosized void. Trajectories also revealed surprisingly strong nonlinearity kinetics, explain model involving coalescence vacancies growing void size for exchange spontaneously proceed was found be 20 atomic vacancies.