Scalable Synthesis of Noble Metal Nanoparticles

Noble metal nanoparticles possess unique size-dependent electronic and optical characteristics and are one of the foremost ‘building blocks’ for nanostructured device fabrication. As such, there is considerable interest in developing continuous-flow processes for large-scale synthesis of noble metal nanoparticles. In this chapter, we describe the results of our work aimed at understanding key process variables that determine particle size distribution in two popular protocols used for lab-scale synthesis of gold and silver colloids. Our understanding of the importance of aggregation and role of the pH of precursor solutions in determining the kinetics and stability of colloidal sols enabled us to propose suitable modifications in process conditions that enabled scalable synthesis of gold and silver nanoparticles. These insights also led to the development of a novel route for low-cost fabrication of silver nanostructures on paper using an inkjet printer.