Electrochemical Heterogeneity at the Nanoscale: Diffusion to Partially Active Nanocubes

How does heterogeneity in activity affect the response of nanoparticles? This problem is key to studying the structure-activity relationship of new electrocatalytic materials. However, addressing this problem theoretically and to a high degree of accuracy requires the use of three-dimensional electrochemical simulations that have, until recently, been challenging to undertake. To start to probe this question, we investigate how the diffusion-limited flux to a cube changes as a function of the number of active faces. Importantly, it is clearly demonstrated how the flux is not linearly proportional to the active surface area of the material due to the faces of the cube not having diffusional independence, meaning that the flux to each face reflects the activity or not of nearby faces. These results have dear and important implications for experimental work that uses a correlation-based approach to evidence changes in activity at the nanoscale.

Automated summary

This study investigates the effect of heterogeneity in activity on the response of nanoparticles and reveals that the number of active faces is not directly proportional to the flux, but is influenced by the activity of nearby faces.