Ferrihydrite的亚微观结构对反应活性的影响

Effect of Ferrihydrite Sub-microstructure on Its Reactivity

以Fe(III)盐为原料、NaOH为沉淀剂、采用三种方法调控制备了ferrihydrite,借助X射线衍射(XRD)、红外光谱(IR)、差热分析(DTA)及其在稀盐酸中的溶解速率等手段对其结构进行了表征,探讨了ferrihydrite的形成环境对其亚微观结构及其反应活性的影响.结果表明,不同方法制备的ferrihydrite的亚微观结构不同,恒pH条件下制备的ferrihydrite结构与α-Fe2O3结构最为相似,更易转化为α-Fe2O3粒子.

Ferrihydrite was prepared by three procedures using Fe（Ⅲ） as a raw material and NaOH as a precipitant. X-ray diffraction （XRD）, infrared （IR） spectroscopy, differential thermal analysis （DTA）, and kinetic dissolution in an acidic medium were employed to characterize the ferrihydrite synthesized by different methods. The effect of ferrihydrite sub-microstructure on its reactivity was investigated. The results showed that the sub-microstructure and the reactivity of ferrihydrite were related to the different preparation procedures. The structure of ferrihydrite prepared by adding Fe（Ⅲ） and NaOH solutions to water simultaneously and at a constant pH is so similar to the structure of hematite that it easily transforms into hematite particles.