The Microstructure and Growth Behavior of Bi_2Fe_4O_9 Superfine Particles Synthesized by Hydrothermal Method

摘要

In this work, Bi_2Fe_4O_9Superfine particles were prepared by hydrothermal method and effects of hydrothermal conditions on the microstructure of Bi_2Fe_4O_9, especially the concentration of OH~-([OH~-]) in initial solutions, were investigated. The results showed that [OH~-] had obvious influences on the growth of Bi_2Fe_4O_9 under the same hydrothermal temperature and hydrothermal time. Phase structure of Bi_2Fe_4O_9unchanged with the increase of [OH~-] and maintained orthorhombic structure. Besides, the microstructure of Bi_2Fe_4O_9 was carefully studied through transmission electron microscopy (TEM). The results suggested that the mechanism of Bi_2Fe_4O_9 growth was Ostwald ripening. In conclusion, Bi_2Fe_4O_9 superfine particles with good morphology and microstructure can be successililly synthesized when the concentration of OH~- is 2 moI/L and hydrothermal conditions are 240°C for 6h.