One-pot synthesis of Bi₂Se₃ nanostructures with rationally tunable morphologies

Shape control has proven to be a powerful and versatile means of tailoring the properties of Bi₂Se₃ nanostructures for a wide variety of applications. Here, three different Bi₂Se₃ nanostructures, i.e., spiral-type nanoplates, smooth nanoplates, and dendritic nanostructures, were prepared by manipulating the supersaturation level in the synthetic system. This mechanism study indicated that, at low supersaturation, defects in the crystal growth could cause a step edge upon which Bi₂Se₃ particles were added continuously, leading to the formation of spiral-type nanoplates. At intermediate supersaturation, the aggregation of amorphous Bi₂Se₃ particles and subsequent recrystallization resulted in the formation of smooth nanoplates. Furthermore, at high supersaturation, polycrystalline Bi₂Se₃ cores formed initially, on which anisotropic growth of Bi₂Se₃ occurred. This work not only advances our understanding of the growth mechanism but also offers a new approach to control the morphology of Bi₂Se₃ nanostructures.