Hydrothermal synthesis and formation mechanism of hexagonal yttrium hydroxide fluoride nanobundles

• Novel Y(OH)2.02F0.98 nanobundles have been successfully prepared by hydrothermal method.
• The branched nanobundles composed of numerous oriented-attached nanoparticles has been studied.
• The growth mechanism is proposed to be ion exchange and precipitation transformation.

This article presents the fabrication of hexagonal yttrium hydroxide fluoride nanobundles via one-pot hydrothermal process, using yttrium nitrate, sodium hydroxide and ammonia fluoride as raw materials to react in propanetriol solvent. The X-ray diffraction pattern clearly reveals that the grown product is pure yttrium hydroxide fluoride, namely Y(OH)2.02F0.98. The morphology and microstructure of the synthesized product is testified to be nanobundles composed of numerous oriented-attached nanoparticles as observed from the field emission scanning electron microscopy (FESEM). The chemical composition was analyzed by the energy dispersive spectrum (EDS), confirming the phase transformation of the products which was clearly consistent with the result of XRD analysis. It is proposed that the growth of yttrium hydroxide fluoride nanobundles be attributed to ion exchange and precipitation transformation.

The formation of yttrium hydroxide fluorides nanobundles can be expressed as a precipitation transformation from cubic NaYF4 to hexagonal NaYF4 and to hexagonal Y(OH)2.02F0.98 owing to ion exchange.Figure optionsDownload as PowerPoint slide