EDTA-assisted hydrothermal synthesis, characterization, and luminescent properties of YPO4·nH2O:Eu3+ (n = 0, 0.8) microflakes and microbundles

•The composition of the product could be changed with different amount of EDTA.•The morphology of the product could be changed with different amount of EDTA.•The formation mechanisms and splitting patterns were put forward.

In this paper, the YPO4:Eu3+ (5%) microflakes and YPO4·0.8H2O:Eu3+ (5%) microbundles have been synthesized by a simple EDTA-assisted hydrothermal method. The X-ray powder diffraction (XRD), thermogravimetric and differential thermal analysis (TG/DTA), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and photoluminescence (PL) were employed to characterize the as-obtained products. It was found that the composition of the product could be changed from YPO4:Eu3+ (5%) to YPO4·0.8H2O:Eu3+ (5%) with a further increase in the amount of EDTA 0.5–1.0 g. The YPO4:Eu3+ (5%) presented the pure tetragonal phase and flake-like microstructure, while the YPO4·0.8H2O:Eu3+ (5%) exhibited the hexagonal phase and bundle-like morphology. The possible formation mechanisms of the two architectures were put forward on the basis of different EDTA amount-morphology experiments. A detailed investigation on the photoluminescence of YPO4·nH2O:Eu3+ (5%) different samples indicated that the luminescent properties of products were strongly dependent on the compositions, morphologies, coordination environment and crystal field symmetry.