Metal Carbide Nanocrystal Nucleation and Growth in a Transition Metal Coordination Polymer

Abstract

The mechanism that governs the conversion of the Co-Prussian blue analogue (PBA) to Co2C was investigated and observed to exhibit lag phase growth behavior that can be fit to the autocatalytic kinetic model. The energetics and activation energies were extracted from the temperature-dependent data. The experimental results provide insight into how to control the size and crystallinity of Co2C, where shorter lag times and smaller sizes occur at higher reaction temperatures and longer times and larger sizes at lower temperatures. Investigation of temperature-dependent growth revealed an R 2 relationship, supporting a surface mediated growth model. In addition, low temperatures lead to higher polycrystallinity in the nanocrystal that grows within the PBA framework.