Wet-chemical route for the preparation of lead zirconate: An amorphous carbon- and halide-free precursor synthesized by the hydrogen peroxide based route

PbZrO₃ (PZ) nanoparticles were synthesized through a halide- and organic-free hydrogen peroxide method at 700 °C for 2 h. Stoichiometric amounts of zirconyl nitrate and lead nitrate were dissolved in a diluted H₂O₂ (aqueous) solution, which was slowly dropped into a solution of H₂O₂ and NH₃ (pH = 11). The precipitate of Pb-Zr, obtained from an exothermic oxy-reduction reaction, was filtered and washed to eliminate all nitrate ions. The precipitate was dried, ground, and calcined between 300 and 1000 °C, for 5 min to 8 h. Tetragonal, lead-rich zirconia solid solution (t-Z) was identified by thermogravimetry-differential thermal analysis, X-ray diffraction, and Raman spectroscopy as an intermediate phase during the calcination process, followed by the crystallization of the orthorhombic PZ phase. The average particle size was estimated to be 50 nm from scanning electron microscopy pictures. The change in the amount of residual t-Z phase in PZ powders was estimated from the Raman spectra.