Anisotropic morphology, formation mechanisms, and fluorescence properties of zirconia nanocrystals

Abstract

ZrO2 nanocrystals with spheres and elongated platelets were systemically prepared through a simple hydrothermal method by the use of ZrOCl2·8H2O and CH3COOK as raw materials. The anisotropic morphology and formation mechanism of the monoclinic and/or tetragonal ZrO2 were investigated by X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscope, and high-resolution transmission electron microscope techniques. The uniform elongated platelets and star-like structures were composed of short nanorods with a diameter of approximately 5 nm and a length of approximately 10 nm. The different morphologies were formed due to the different contents of CH3COO− and Cl− and their synergy. The fluorescence band position and the band shape remained about the same for excitation wavelengths below 290 nm and the different morphologies of the nanocrystals.