The Morphology Control of BaTiO 3 Particles Synthesized in Water and a Water/Ethanol Solvent

The experimental conditions for the growth of shape‐controlled BaTiO 3 particles in NaOH and Ba ( NO 3 ) 2 aqueous and water/ethanol solutions using various TiO 2 ‐containing precursors were studied at 80°C–100°C. The different chemistries and physical characteristics of the precursors resulted in different BaTiO 3 formation rates and morphologies . Nanocrystalline anatase led to irregularly shaped BaTiO 3 particles, whereas star‐like, single‐crystalline BaTiO 3 particles grew from aerogel TiO 2 and sodium titanate ( NT ) belts in alkaline aqueous solutions. With the addition of ethanol, the star‐like BaTiO 3 particles changed to square‐like, the size of which decreased with an increase in the ethanol content. The electron microscopy observations supported a dissolution–precipitation mechanism as the primary reaction mechanism for the formation of BaTiO 3 nanocrystals, which further aggregated into single‐crystalline star‐ or square‐like particles by oriented attachment. The modification in the water solution with ethanol is believed to influence both the nucleation and aggregation process and consequently influence the particle shape and size.