Plasmon-Mediated Reconfiguration of Twin Defect Structures in Silver Nanoparticles

Abstract

Defects in metal nanoparticles can play a critical role in directing interfacial processes, such as catalytic reactions, at the surface of these materials. Interest in understanding the fundamental role of crystalline defects in controlling nanoparticle properties has inspired exploration of synthetic methods for tuning the twin defect structure of metal nanoparticles. However, controlling this structural parameter is a challenge due to the subtle reaction kinetics that dictate defect formation. For plasmonic silver (Ag) nanomaterials, the potential for light-induced growth provides a unique opportunity for driving structural reconfiguration between nanoparticle morphologies with different twin defect structures. We report a plasmon-mediated reconfiguration pathway in which {111}-faceted Ag nanoparticles are sequentially converted: first from planar twinned triangular Ag prisms to multiply twinned icosahedra (along with a smaller subpopulation of other twinned shapes), subsequently to multiply twinned Ag nanospheres, and finally back to planar twinned triangular Ag prisms. These consecutive reconfiguration processes occur as a result of the precise manipulation of reaction kinetics using a combination of illumination wavelength and pH. This method provides a valuable tool for reconfiguring, recycling, and regenerating Ag nanoparticles.