Preparation and characterization of tetragonal-ZrO2 nanopowders by a molten hydroxides method

Pure tetragonal-ZrO2 nanopowders are prepared by a molten hydroxides method, using hydrated zirconium nitrate as the starting material at 200 °C. X-ray diffraction analysis and transmission electron microscopy observation reveal that the nanopowders exhibit poor crystalline quality. After heat treated at 400 °C for 10 h in air, the nanopowders are crystalline with size range of ∼10–12 nm and most of them are agglomerated. The formation mechanism of the ZrO2 nanopowders has been proposed. The heat treated nanopowders have a BET surface area of ∼27.3 m2/g due to agglomeration. The photoluminescence of the heat treated nanopowders has been investigated at room temperature.