Phase-Tunable Synthesis of Monodisperse YPO4:Ln3+ (Ln = Ce, Eu, Tb) Micro/Nanocrystals via Topotactic Transformation Route with Multicolor Luminescence Properties
摘要:
A novel aqueous-based and phase-selected synthetic strategy toward YPO4:Ln(3+) (Ln = Ce, Eu, Tb) micro/nanocrystals was developed by selecting specific precursors whose structure topotactically matches with the target ones. It was found that layered yttrium hydroxide (LYH) induced the formation of hexagonal-phased h-YPO4.0.8H(2)O with the crystalline relationship of [001]LYH//[0001]h-YPO4.0.8H(2)O, while the amorphous Y(OH)CO3 favored the formation of tetragonal-phased t-YPO4. We also systematically investigated the influence of Na2CO3/NaH2PO4 feeding ratio on the evolutions of morphology and size of the h-YPO4.0.8H(2)O sample, and we also obtained a novel mesoporous nanostructure for t-YPO4 single crystalline with closed octahedron shape for the first time. Besides, the multicolor and phase-dependent luminescence properties of the as-obtained h-YPO4.0.8H(2)O and t-YPO4 micro/nanocrystals were also investigated in detail. Our work may provide some new guidance in synthesis of nanocrystals with target phase structure by rational selection of precursor with topotactic structural matching.
The present work reports a self-sacrificing template strategy to synthesize porous α-NaYF4 microspheres via the reaction of as-prepared Y(OH)CO3·H2O@SiO2 with NH4F and NaNO3 solutions.