Synthesis of Nanocrystalline Zirconia Using Sol−Gel and Precipitation Techniques

Abstract

Nanocrystalline zirconia samples having predominantly tetragonal crystalline phase were synthesized using sol-gel and conventional precipitation techniques from zirconium hydroxide obtained by the hydrolysis of both zirconium propoxide and zirconium oxychloride precursors. Thermal drying of zirconium hydroxide gel in an oven (110 °C, 12 h) results in lower crystallite size (11-13 nm) as compared to drying under vacuum (50 mbar, 70 °C), which shows higher crystallite size (20-21 nm) during both sol-gel and conventional precipitation synthesis. The progressive transformation of tetragonal to monoclinic phase of zirconia with increasing calcination temperature was observed to be related to the critical crystallite size and lattice strain. Sol-gel synthesis was found to be advantageous because of the stabilization of tetragonal phase at higher temperature, whereas complete phase transformation was observed in the samples prepared by precipitation method at 600-700 °C temperature. Sol-gel synthesis resulted in spherical-shaped particles whereas cubic-/ rectangular-shaped particles of varying sizes were predominantly formed by conventional precipitation synthesis.

Synthesis of zirconium oxide nanoparticle by sol-gel technique

“…They found out that sol-gel synthesis showed the stabilization of tetragonal phase at higher temperature. The zirconia crystallite size is 13-28nm for solgel synthesis and 11-37nm for precipitation synthesis [4]. Ward & Ko synthesis zirconium oxide by sol-gel preparation.…”

Síntese E Caracterização De Óxidos Mistos De Zircônio

“…(2θ=28,4º, 31,6º, 24,2º e 34,1º), segundo Tyagi et al (2006). Na Figura 1(B), percebe-se a transformação da fase tetragonal em monoclínica, na qual se observa que as bandas 2θ=28,4º, 31,6º, 24,2º e 34,1º se tornam mais intensas e destacadas.…”

“…A sua característica especial é possuir tanto sítios ácidos quanto básicos de Lewis, podendo ser utilizado tanto em reações de desidrogenação quanto de desidratação de álcoois, sendo particularmente um excelente receptor para o íon O 2- (Tyagi et al, 2006). Contudo, o óxido pode ser considerado mais ácido ou básico conforme o seu método de preparação, o qual influencia diretamente em propriedades como a estrutura cristalina, distribuição de tamanho, volume total dos poros, área superficial e distribuição de sítios básicos e ácidos do ZrO 2 (Aramendía et al, 1997).…”

Tuning the phase composition and particle characteristics of partially stabilized yttria and ceria co-doped zirconia nanocrystals via a sol–gel process with sodium chloride as an additive

“…1A and 3A) using Scherer's formula D¼ (0.89λ) / (β cosθ) [32], where D is the crystallite size, λ is the wavelength of CuKα radiation (λ¼ 1.5405 Å ), β is the full width at half maximum (FWHM, in radians) of peaks and θ is the diffraction angle [33] for crystal planes, such as peak at 2θ of 30.51 for (1 1 1) crystal plane of t-ZrO 2 and 2θ of 31.61 for (1 1 1) of m-ZrO 2 . It can be seen from Table 1 that the crystallite size of PS-YCZ-NCs-1 and PS-YCZ-NCs-2 ranged from 17.4 nm to 29.8 nm, and only a slightly change of crystallite size was observed due to the addition of NaCl.…”