BiFeO3的水热合成及其结构演变

Structure Evolution of Bismuth Ferrite Synthesized by Hydrothermal Route

摘要:

以Fe(NO3)3·9H2O 和Bi(NO3)3·5H2O为原料、NaOH为矿化剂，采用水热法成功制备了BiFeO3粉体，研究了BiFeO3粉体在不同反应条件下的相结构与微观形貌的演变。结果表明：低的反应温度下只有杂相生成，提高反应温度使得杂相逐渐减少，有效地促进BiFeO3相的合成；反应时间的延长也有助于减少杂相，而较低的矿化剂浓度能够获得纯BiFeO3，当NaOH浓度为1 mol/L时，在170 ℃反应24 h可以获得纯BiFeO3粉体。另外，通过控制不同的反应条件，可以获得多种形貌的产物，如薄片、球形体、纳米颗粒、纳米线、四面体，实验发现，适中的反应温度、时间和矿化剂浓度可以得到大尺寸的球形体（~10 μm），而反应时间的延长则会促进一维纳米结构及纳米颗粒的生长

Abstract:

The Bismuth ferrite (BiFeO3) powders were hydrothermally synthesized using Fe(NO3)3·9H2O and Bi(NO3)3·5H2O as starting materials, and NaOH as a mineralizer. Phase structure and micro-morphology of BiFeO3 powders under various reaction conditions were investigated. Results show that only impurity phase is observed at low reaction temperature. With increasing reaction temperature, the impurity phase is reduced and the BiFeO3 phase is significantly increased. The extension of reaction time could reduce impurity phase, and pure BiFeO3 is achieved with low mineralizer concentration of 1 mol/L calcined at 170 °C for 24 h. Furthermore, the products with different morphologies are obtained by adjusting reaction condition, such as slices, spheroids, nano-particles, nano-wires, tetrahedrons. It is found that large-scale spheroids (~10 μm) could be obtained with moderate reaction temperature, time and mineralizer concentration, and the increase of reaction time promotes the growth of one-dimension nano-structures and nano-particles