Preparation Of ZrO₂ Nanocrystal And Morphology Control By Hydrothermal Method

The spherical ZrO₂ nanoparticles was prepared using ZrOCl2·8H₂O and NH₃·H₂O asstarting materials, and ethylenedilamine as organic addictive by hydrothermal methods. Inaddition, the hydrothermal factors such as hydrothermal temperature, hydrothermal timeand concentration of ethylenedilamine were discussed. The zirconia crystallites werecharacterized by X-ray diffraction (XRD), Raman spectroscopy and transmission electronmicroscopy (TEM). The results indicated that increase of hydrothermal temperature,hydrothermal time and the ethylenedilamine concentration can promote the crystallitegrowth of zirconia.Then ZrOCl₂·8H₂O and NH₃·H₂O were used as raw materials, and NaOH was usedfor mineralizer to obtain the ideal short rod-like zirconia crystallite. The results show thatconcentration of mineralizer NaOH was an important factor for promotion of crystallinityby X-ray diffraction (XRD) and Raman spectroscopy. Following the increase ofconcentration of mineralizer NaOH in a lower scale, zirconia samples prepared usingNaOH as mineralizer belong to the mixture of monoclinic phase and tetragonat phase bythe comparison of standard Raman shifts of zirconia crystallite and XRD pattern, andtransformation of crystal phase was from tetragonal phase to monoclinic phase. Themorphology of zirconia transforms gradually from spherical nanoparticle to short nanorod.When the concentration of NaOH continues to increases, the short rod-like zirconiacrystallite grows into the longer and wider rod with the decreasing ratio of length/width byscanning electron microscopy (SEM).Afterwards, using above experimental conditions and KOH as mineralizer, the shortrod-like zirconia crystallite was also prepared by hydrothermal reaction. The morphologyof zirconia crystallite was observed by transmission electron microscopy(TEM) andscanning electron microscopy(SEM).