Synthesis and Morphology of KNbO_3 Powders via Hydrothermal Method

摘要

In this research, potassium niobate (KNbO_3) powder was synthesized successfully for 6-24 h in 15 M of KOH solutions at 120-200°C via the hydrothermal method. The effects of reaction temperatures and reaction times on the precipitation of KNbO_3 powders were investigated. A hydrothermal precursor yielded a pure single phase KNbO_3 for 18 h at 150°C. When the reaction time increased to 24 h, the morphology of KNbO_3 changed from an irregular shape to a rod- or bar-shape. The reaction temperature had a marked effect on both structure and phase formation, while the reaction time could affect morphology. The direct synthesis of KNbO_3 from Nb_2O_5 and aqueous KOH under hydrothermal conditions therefore represents an easy method for the preparation of this compound.