Revealing Bismuth Oxide Hollow Nanoparticle Formation by the Kirkendall Effect

We study the formation of bismuth
oxide hollow nanoparticles by
the Kirkendall effect using liquid cell transmission electron microscopy
(TEM). Rich dynamics of bismuth diffusion through the bismuth oxide
shell have been captured in situ. The diffusion coefficient of bismuth
through bismuth oxide shell is 3–4 orders of magnitude higher
than that of bulk. Observation reveals that defects, temperature,
sizes of the particles, and so forth can affect the diffusion of reactive
species and modify the kinetics of the hollowing process.