Shape control of silver nanoparticles and their stability on Al2O3

Abstract

From antimicrobial studies to photonic devices, silver nanoparticles have been an exciting material, investigated for decades. Much of the efforts have been focused on tunable size, shape and optical properties of silver colloids. Although many advancements have been made there remain key limitations, including oxidation, and reactivity, especially in comparison to more stable gold nanomaterials. In this work, we present a method for stabilizing silver nanoparticles on aluminum oxide scaffolding, mitigating the oxidation and aggregation typical of silver particles, while maintaining their highly tunable plasmonic properties. Herein, alumina stabilized silver nanoparticles are subjected to photochemical shape control where the final particle morphology is dependent on whether the Al₂O₃ is in a solid or colloid phase. This work provides more insight into the complex mechanism(s) of nanoparticle shape control. Particles, with tunable plasmon modes achieved across the visible spectrum, provide optical properties of great relevance to the fields of chemical sensing, catalysis, and photonics while maintaining long-term stability.