不同晶化度γ-FeOOH的合成及其液相转化研究

Synthesis of Different Crystalline γ-FeOOH and Their Liquid Phase Transformation

进行了空气氧化Fe(OH)2悬浮液,EDTA作用下可见光诱导,不同温度(14～20℃)制备不同晶化度γ-FeOOH的研究,进行了其沸腾回流液相转化历程的探讨.结果表明:随温度的升高,γ-FeOOH的晶化程度变差;而γ-FeOOH的晶化程度越差,在液相沸腾回流时就越易转化成α-Fe2O3,反之则易转化为α-FeOOH.在pH近中性,微量Fe(Ⅱ)存在条件下低晶态的γ-FeOOH可以快速转化为均匀球形的α-Fe2O3.

The preparation of different crystalline degree lepidocrocite （γ-FeOOH） from air oxidation of Fe（OH）2 under irradiation by visible light in the presence of trace EDTA at different temperatures （14~20 ℃） were described. And the mechanism of the liquid phase transformations of γ-FeOOH was also studied. The experimental result showed that the crystalline degree of γ-FeOOH became poor with the increase of the temperature; the lower the crystallization degree of γ-FeOOH, the easier of the transformation to hematite （α-Fe2O3） by boiling reflux method; the goethite （α-FeOOH） was obtained from the liquid phase transforma- tions of the high crystalline γ-FeOOH; the low crystalline γ-FeOOH could transform to spherical α-Fez03 rapidly under a near-neutral pH condition and in the presence of trace Fe（Ⅱ）.