Effects of TiO2 Sources on Crystalline Phase and Morphology of BaTiO3 Nanoparticles Prepared via Wet Chemical Route

Barium titanate (BaTiO₃) nanoparticles were synthesized via a hydrothermal method using barium hydroxide (Ba(OH)₂) and titanium oxide (TiO₂) as starting materials. The present study investigates the influence of TiO₂ sources on BaTiO3 nanoparticle crystallinity and morphology. A comprehensive statistical analysis was conducted, revealing a direct correlation between the phase and size of the TiO₂ and the properties of the BaTiO₃. Anatase TiO₂, with a size ranging from 5-30 nm, was found to yield uniform spherical BaTiO₃ nanoparticles with sizes ranging from 66.1 ± 9.4 nm to 80.3 ± 10.8 nm. Conversely, rutile TiO₂, with a size of 10 nm, yielded irregular particles with an average size of 386.6 ± 146.99 nm. XRD analysis demonstrated that smaller anatase TiO₂ (5 nm) exhibited a propensity to favor cubic-phase BaTiO₃, while larger anatase TiO₂ (10–30 nm) exhibited a propensity to promote tetragonal-phase dominance. Conversely, rutile-derived BaTiO₃ exhibited a mixed phase (tetragonal-to-cubic ratio: 2:3). Kinetic studies of precursor synthesis have demonstrated that 5 nm anatase TiO₂ facilitates the rapid nucleation of BaTiO₃ within 30 seconds, reaching full conversion. This is in contrast to the slower kinetics caused by larger anatase TiO₂ and the negligible reactivity observed for rutile TiO₂. These findings underscore the critical role of TiO2 phase and size in tailoring BaTiO3 nanoparticles for advanced dielectric applications, enabling precise control over particle size (60–80 nm) and crystallinity through precursor engineering.