Template-Free Hydrothermal Synthesis of Octahedron-, Diamond-, and Plate-like ZrO₂ Mono-Dispersions

Abstract

Anisotropic ZrO2 particles with octahedron-, diamond- and plate-like morphologies are successfully synthesized by a facile hydrothermal treatment approach using NaBF4 as mineralizer. The concentration of mineralizers play a crucial role on the formation of shape-controlled ZrO2 particles thus affect the particle size. With the increasing concentration of mineralizer, the crystalline sizes of the primary single-crystal and the secondary particle size both increase. With the introduction of NaBF4, F− plays an essential role in tuning the crystallinity and size of primary ZrO2 nanorods along [001] direction. The synergistic effect of F− and B3+ result in different epitaxial growth rate. And the secondary particles mainly crystallize on the small primary nanoparticles through the oriented attachment mechanism. The as-prepared ZrO2 particles with different sizes and shapes exhibit different photocatalytic efficiency for the degradation of organic dyes. Under UV irradiation, the highest MB degradation rate of 88% was observed within 60 min for ZrO2 photocatalyst synthesized with 0.01 mol/L NaBF4 mineralizer.

Keywords

• hydrothermal
• zirconia
• morphology
• NaBF₄