文摘
This work reports self-assembled uniform monodisperse Na<sub>xsub>Y(OH)<sub>ysub>F<sub>3+x–ysub> (0 < x < 1, 0 < y < 3) mesocrystals with tunable morphology and chemical composition obtained from a hydrothermal ion-exchange reaction. Detailed crystal structure analysis illustrates that the special crystal structure of Na<sub>xsub>Y(OH)<sub>ysub>F<sub>3+x–ysub> (0 < x < 1, 0 < y < 3) facilitates the pH-mediated ion-exchange process. A possible topochemical-based mechanism has been proposed to this ion-exchange process. By carefully adjusting the pH value of the solution, the tunable three-dimensional (3D) Na<sub>xsub>Y(OH)<sub>ysub>F<sub>3+x–ysub> (0 < x < 1, 0 < y < 3) mesocrystal architectures are obtained through an oriented self-assembly. The photoluminescence properties of the rare earth ions (such as Eu<sup>3+sup>, Tb<sup>3+sup>, and Ce<sup>3+sup>) doped as-prepared mesocrystal samples are investigated, and multicolor emissions are realized.