红外光谱技术在铁氧化物形成研究中的应用

Application of IR Spectra in the Studies on the Formation of Iron (Hydr)oxides

以红外光谱(IR)和X射线衍射(XRD)为主要表征手段,研究了在中性环境中微量Fe(Ⅱ)离子存在时氢氧化铁凝胶的相转化过程,获得了铁氧化物液相形成过程的重要信息.结果表明:微量Fe(Ⅱ)离子存在时氢氧化铁凝胶的相转化机制与没有Fe(Ⅱ)离子时不同,除生成αFeOOH和αFe2O3外,还生成了新的物种γFeOOH.γFeOOH的生成与温度、pH、阴离子种类等反应条件有关.

The phase transformation of Fe(OH)_3 gel in the presence of trace amounts of Fe(Ⅱ) ions was studied by using IR spectra and XRD.Some important information on the formation of iron (hydr)oxides in solution was obtained.The results show that the phase transformation mechanism of Fe(OH)_3 gel in the presence of Fe(Ⅱ) ions is different from that in the absence of Fe(Ⅱ) ions.In the system with Fe(Ⅱ) ions,a new product γ-FeOOH forms besides α-FeOOH and α-Fe_2O_3.The results also show that the formation of γ-FeOOH is related to such factors as temperature,pH and the type of anions and so on.