Influence of precursors and mineralizers on phase formation in ZrO2 nanoparticles synthesized by the hydrothermal method

Abstract

In this study, ZrO2 nanoparticles were synthesized by the hydrothermal method using different precursors and mineralizers. X-ray diffraction revealed that the choice of synthesis components has a significant impact on the phase composition and crystallinity of the resulting ZrO2 nanoparticles. Raman spectroscopy indicated that varying the combinations of precursors and mineralizers enables the formation of both cubic and tetragonal phases of ZrO2 within the samples. Transmission electron microscopy showed that the particle size ranges from 4 to 14 nm, with crystalline samples predominantly containing particles in the 5–6 nm range. In amorphous samples, nuclei with sizes between 5 and 10 nm were observed. TGA analysis demonstrated that all samples contain a substantial amount of synthesis by-products, reaching up to 30% of the total mass. Spectroscopic analysis of the optical properties determined that samples with more than 9% by-product content exhibit the highest absorption in the UV subrange. The phase stability of ZrO2 nanoparticles and the effect of temperature on the crystallization of amorphous samples were estimated using high-temperature X-ray diffraction.