纳米Fe₃O₄晶粒的水热制备及影响因素研究

【作者】 邹大香；

【导师】 李新建；

【作者基本信息】 郑州大学 ， 凝聚态物理， 2003， 硕士

【摘要】 纳米Fe₃O₄具有重要的工业应用价值，而如何实现对其纯度、晶粒尺寸及分布的精确控制则是应用的关键。本文利用水热法合成纳米Fe₃O₄并系统研究了反应溶液的起始pH值、处理温度和处理时间等因素对其晶粒纯度和尺寸的影响，得到了以下结果： 1．反应溶液的起始pH值是影响纳米Fe₃O₄晶粒纯度的决定因素。起始pH=11是制备纯相纳米Fe₃O₄的最佳pH值。 2．水热处理温度是影响纳米Fe₃O₄晶粒纯度和尺寸的重要因素。只有在处理温度≥150℃时才可以得到纯相的纳米Fe₃O₄，在此基础上，升高处理温度将使生成的纳米Fe₃O₄晶粒变大。 3．水热处理时间是影响纳米Fe₃O₄晶粒纯度和尺寸的另一个重要因素。处理温度不同，得到纯相纳米Fe₃O₄所需的最短反应时间就不同。处理温度较高时，所需的最短处理时间短；处理温度较低时，所需的最短处理时间长。无论采用何种处理温度，处理时间的延长都会导致纳米Fe₃O₄晶粒尺寸的增大。 上述研究结果为通过改变制备条件实现对纳米Fe₃O₄晶粒纯度和尺寸的有效控制奠定了可靠的基础，并为可能的实际应用做了实验上的准备。更多还原

【Abstract】 Fe3O4 nanocrystal is valuable in industrial applications, in the process, the precise control of the purity, the grain size as well as its distribution are key factors. Here we report that Fe3O4 nanocrystal was prepared by hydrothermal technique, and the effects of hydrothermal conditions, the pH value of the starting solution, the processing temperature and the processing time, on the purity and the grain size of Fe3O4 were studied systematically. Some results were achieved.1. The choice of the pH value of the starting solution is decisive for obtaining high-purity Fe3O4 nanocrystal, 11 is the best pH value for synthesizing high-purity Fe3O4 nanocrystal.2. The processing temperature is important to control the purity and the grain size of as-synthesized Fe3O4 nanocrystal. The highly purified Fe3O4 nanocrystal could only be obtained at a temperature higher than 150℃, and based on which, the raise of the temperature would result in an increment of the grain size of Fe3O4 nanocrystal.3. The processing time is also important to control the purity and the grain size of as-synthesized Fe3O4 nanocrystal. At various temperature permitted, the minimum time needed to obtain high-purity Fe3O4 nanocrystal was different. The higher the processing temperature adopted, the shorter the minimum time is needed; the lower the processing temperature adopted, the longer the minimum time is needed. Furthermore, longer processing time would lead to an increment of the grain size of Fe3O4 nanocrystal.These researches make it possible to control the purity and the grain size of Fe3O4 nanocrystal effectively through changing the synthesizing conditions, and might have set up a credible foundation for practical applications of the material.更多还原