Shape evolution process of two-dimensional CdSe nanocrystals altered by seed concentration

Two-dimension (2D) nanocrystals have attracted considerable attention for their exceptional optical, electrical and catalytic properties. But the formation mechanism about 2D nanocrystals remain in debate. The shape evolution can provide the platform for more accurate and full understanding of the formation mechanism about 2D nanocrystals. In this work, we used the purified CdSe quantum dots as seeds to grow the 2D nanocrystals. The shape of CdSe 2D nanocrystals can change from rectangular 2D nanocrystals to square 2D nanocrystals with increasing growth time. This shape evolution process can be adjusted by addition different concentrations of CdSe seeds. With reducing the concentration of CdSe seeds, the shape evolution process of CdSe 2D nanocrystals was accelerated. The dissolution and recrystallization behaviors play a key role in the shape evolution of CdSe 2D nanocrystals.