Preparation of amorphous ZrO2 powders by hydrothermal-assisted sol-gel method

Amorphous ZrO2 exhibited broad application prospect as support materials. Herein, amorphous ZrO2 powders were prepared by a novel hydrothermal-assisted sol-gel route using zirconium oxychloride (ZrOCl2⋅8H2O) as zirconium source and ammonia water (NH3⋅H2O) as precipitant. The effects of pH, zirconium source concentration, and hydrothermal treatment on the properties of ZrO2 powders were investigated. The phase structure and microstructure were also investigated. The proprieties of the powders obtained from hydrothermal-assisted sol-gel were compared with those of conventional sol-gel method. The particle size of sample obtained from hydrothermal-assisted sol-gel (80 nm) was smaller than that of conventional sol-gel (210 nm). And the purity was also higher (99.95 vs 98.56 wt%). These results demonstrated that the obtained ZrO2 powders have amorphous structure, uniform and small particle size, rough and loose surface, and high purity.