Hydrothermal Synthesis of Bismuth Sodium Titanate Nanowires and Forming Mechanism

The Na0.5Bi0.5TiO3 nanowires with perovskite structure were successfully synthesized by the hydrothermal method using Bi(NO3)3―5H2O, H1.07Ti1.73O4―nH2O and NaOH as the starting materials. The products were characterized by X―ray powder diffraction (XRD), field emission scanning electron microscope (FESEM), transmission electron microscope (TEM) and energy dispersive spectroscope (EDS), respectively. The phase structure, morphology, and chemical compositions of products synthesized at 200 by hydrothermal process for different times were investigated and the forming mechanism of nanowires was introduced. The results indicate that H1.07Ti1.73O4―nH2O is a compound with lepidocrocite―like layered structure, and the Na+, Bi3+ ions can exchange with H3O+ in the interlay space of plate―like titanates in the hydrothermal process. Then the plate―like titanates are transformed into plate―like Na0.5Bi0.5TiO3 particles by in situ reaction. With the hydrothermal reaction progressing, the plate―like Na0.5Bi0.5TiO3 particles split into nanowires. The nanowires are well dispersed with perovskite structure. The width of nanowire is ranging from 30 nm to 150 nm and the length is about several micrometers to tens of micrometers.