Self-optimising continuous-flow hydrothermal reactor for nanoparticle synthesis†

Abstract

An autonomous continuous-flow, hydrothermal synthesis reactor, capable of self-optimising nanoparticle size using an in-line characterisation technique and machine learning is presented. The developed system is used for synthesis of hematite (α-Fe₂O₃) nanoparticles across three process variables, optimising for a target particle size. Optimisation is achieved in under 7 h with only 500 ml of 0.1 M Fe(NO₃)₃·9H₂O aqueous stock solution used, and without human intervention.