Continuous Synthesis of Monodisperse Ag Nanocubes

Abstract

The precise control of both the size and shape of Ag nanoparticles strongly influences their optical properties. Although the synthesis of Ag nanocubes with sharp corners and edges has been demonstrated, the ability to scale these approaches with high selectivity remains elusive. In this study, a continuous flow microwave-assisted reactor was used to separate nucleation from growth events, which provides a method to synthesize very uniform single crystalline Ag nanocubes. Nucleation in the microwave zone was enhanced through seed-mediated processes by sulfide formation, and a chemical regulator was used in the growth zone to further improve the sharpness of the edges of the nanocubes. Transmission electron microscopy and optical properties were used to optimize the reaction conditions and Ag nanocubes with edge lengths of 28 and 45 nm were readily synthesized with narrow particle size distributions and high selectivities (>70%). Nanocubes with 28 nm edge lengths were used to prepare films to demonstrate t...