Formation of YF3 nanocrystals and their self-assembly into hollow peanut-like structures

A simple hydrothermal route has been used to prepare hollow peanut-like structures of orthorhombic YF3 by using a suitable tetrafluroborate complex as the fluoride source. The as-synthesized products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). Four tetrafluroborate complexes-NaBF4, NH4BF4, KBF4, and HBF4-were examined in this synthetic procedure. YF3 nanocrystals formed from NaBF4, NH4BF4, or KBF4 were found to self-assemble into hollow peanut-like structures. Time-dependent studies of the reactions have been conducted to reveal the morphological evolution, and the possible mechanistic pathways in the formation of the hollow structures are proposed.