Scaling up the Production of Colloidal Nanocrystals: Should We Increase or Decrease the Reaction Volume?

Recent progress in facet‐controlled syntheses has started to produce nanocrystals with great promise as the next‐generation catalysts for a variety of applications. To move from academic studies to industrial applications, however, one has to address the issue of scaling up a synthesis that has been commonly conducted in a batch format. There are two opposite approaches to scaling up the production of colloidal nanocrystals: increasing and decreasing the reaction volume. Contrary to conventional wisdom, continuous flow synthesis based on droplets is expected to provide a more practical platform for scaling up the synthesis. Here we highlight recent progress in using droplet reactors for the synthesis of colloidal noble‐metal nanocrystals with controlled sizes and shapes, with an aim towards high‐volume production.