Synthesis of ZrO2 and TiO2 nanocrystalline powders by hydrothermal process

In present work, nanocrystalline zirconia and titania were synthesized by hydrothermal treatment of zirconyl ZrO(NO3)2 and titanyl TiO(NO3)2 nitrates aqueous solutions and amorphous gels of the corresponding hydroxides. The hydrothermal synthesis was performed in a wide range of temperatures (150–250 °C), concentration of starting solutions (0.25–0.5 M) and duration of the process (from 10 min to up to 24 h). The hydrothermal treatment at high pressure about 2.0–4.0 GPa was also carried out. The products were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and BET. Particle sizes, morphology and properties of the products were investigated. The influence of hydrothermal synthesis conditions on ZrO2 and TiO2 phase compositions were established.