From Hot-Injection Synthesis to Heating-Up Synthesis of Cobalt Nanoparticles: Observation of Kinetically Controllable Nucleation

Almost equal: Particle nucleation in the widely studied hot‐injection synthesis of magnetic cobalt nanoparticles (see TEM image) was found to take place well after the injection and to be temperature‐controlled. This insight into particle nucleation led to a technologically relevant heating‐up synthesis of nearly monodisperse cobalt nanoparticles on a multigram scale. The particle size could be tuned simply by adjusting the heating rate.