Surface reaction characteristics at low temperature synthesis BaTiO_3 particles by barium hydroxide aqueous solution and titanium tetraisopropoxide

摘要

Well-crystallized cubic phase BaTiO_3 particles were prepared by heating the mixture of barium hydroxide aqueous solution and titania derived from the hydrolysis of titanium isopropoxide (TTIP) at 328 K, 348 K or 368 K for 24 h. The morphology and size of obtained particles depended on the reaction temperature and the Ba(OH)_2/TTIP molar ratio. By the direct hydrolytic reaction of titanium tetraisopropoxide, the high surface area titania (TiO_2) was obtained. The surface adsorption characteristics of the titania particles had been studied with different electric charges OH~- ions or H~+ ions. The formation mechanism and kinetics of BaTiO_3 were examined by measuring the concentration of [Ba~(2+)] ions in the solution during the heating process. The experimental results showed that the heterogeneous nucleation of BaTiO_3 occurred on the titania surface, according to the Avrami's equation.