Atomic imaging reveals in-situ growth behavior of bi nanoparticles by high-energy electron irradiation

Herein, we present an in-situ investigation of Bi nanoparticles (NPs) growth on BiVO4 substrates using highenergy electron beams in transmission electron microscopy (TEM). High-Resolution (HR)TEM images at atomic level reveal a four-step growth mechanism in which Bi NPs transform from metastable droplets to solid nanocrystals. The disappearance behavior is essentially opposite to the growth behavior, with the exception that the Bi particles do not exhibit droplet-like morphology throughout the disappearance. As demonstrated, the aggregation behavior is significantly influenced by particle size, lattice matching degree and interparticle distance. These findings are significant for the practical use of bismuth-based materials in irradiation environments.