In situ investigation of bismuth nanoparticles formation by transmission electron microscope

Bismuth (Bi) nanoparticles are prepared by using NaBi(MoO4)(2) nanosheets in the beam of electrons emitted by transmission electron microscope. The formation and growth of Bi nanoparticles are investigated in situ. The sizes of Bi nanoparticles are confined within the range of 6-10 nm by controlling irradiation time. It is also observed that once the diameter of nanoparticles is larger than 10 nm, the Bi particles are stable as a result of the immobility of large nanoparticles. In addition, some nanoparticles on the edges form nanorods, which are explained as the result of a coalescence process, if the irradiation period is longer than 10 min. The in situ research on Bi nanoparticles facilitates in-depth investigations of the physicochemical behavior and provides more potential applications in various fields such as sensors, catalysts and optical devices.