Novel Chiral Wire–like Bi Nanoparticle Assembly: In–situ Studies on Structural Evolution from (BiO)2CO3 Nanowires Under Electron–beam Irradiation

Abstract

The temporal in-situ observation is of great benefit to the understanding of synthetic strategies in materials science. Herein, for the first time, we report the in–situ monitoring of decomposition of (BiO)2CO3 nanowires under the electron–beam irradiation using a transmission electron microscope (TEM), that produces an intriguing chiral wire–like bismuth (Bi) nanoparticle assembly. The decomposing process of (BiO)2CO3 nanowire was characterized by employing three-dimensional (3D) TEM, selected area electron diffraction (SAED), and high–resolution TEM (HRTEM). It was demonstrated that the (BiO)2CO3 nanowire decomposed into Bi nanoparticles through Bi6O7 intermediates. Bi6O7 nanodot arrays appeared along (013) and () crystal planes of (BiO)2CO3 nanowire with a single orientation relationship of {[001]BCO‖[001]BO, [010]BCO‖[100]BO}. A chiral helix of Bi–nanoparticle assembly formed in random orientation through oxygen–removal of Bi6O7. This work has not only observed the in–situ decomposing process of (BiO)2CO3 nanowires but also demonstrated a facile approach for generating novel chiral Bi nanostructure via electron–beam irradiation, implicating the potential of developing nanomaterials with new tunable nanostructures.