Synthesis of PbTiO3 nanoplates by two-step hydrothermal method with pH-adjusting agent of ammonia solution

PbTiO3 nanoplates were synthesized by a two-step hydrothermal method, and ammonia solution was chosen as a pH-adjusting agent. The effect of ammonia concentration in the second-step precursors, Pb-Ti feedstock concentration, reaction temperature, and time on crystallization and morphologies of PbTiO3 nanocrystals was investigated. The typical single-crystal PbTiO3 nanoplates with stair-like edge were formed, as the nominal ammonia concentration in the first-step precursors was 8.8 mol/L, the nominal ammonia concentration in the second-step precursors was 4.4 mol/L, the nominal Pb-Ti feedstock concentration was 0.05 mol/L, and they were synthesized at 200 degrees C for 20 h. The thickness of the PbTiO3 nanoplates was about 45 nm, and the lateral size was about 400 nm. The ammonia solution played an important role in the formation of PbTiO3 nanoplates, and the growth mechanism of PbTiO3 nanoplates synthesized by the two-step hydrothermal method in ammonia solution was discussed.