铁的氢氧化合物稳定相α,β-FeOOH的表征及光谱分析

Characterization and Spectral Analysis of the Stable Mineral Phases α,β-FeOOH Included in Iron Oxyhydroxides

铁的氢氧化合物稳定相针铁矿(α-FeOOH)及四方纤铁矿(β-FeOOH)的合成材料因具有纳米颗粒粒径、较高比表面积,在工业生产和环境治理中被广泛应用。α,β-FeOOH作为重金属等污染物的吸附材料尤受关注。但其合成过程中溶液pH值和反应条件(如不同温度下加热或室温磁力搅拌等)对α,β-FeOOH矿物材料晶型、颗粒形貌、尺寸和界面特性的影响及其与矿物环境功能的相关性报道较少。故本工作基于Fe(NO_3)_3和FeCl_3溶液在一定pH值范围内分别易于形成α-FeOOH和β-FeOOH稳定相,利用X射线衍射仪、透射/扫描电子显微镜和激光粒度分析仪对加热(40和70℃)和磁力搅拌(25℃)条件下形成的矿物α,β-FeOOH的晶型和颗粒形貌结构进行了鉴定与表征,同时利用红外光谱仪测定了矿物表面的特征结构基团。研究结果表明,40和70℃反应温度下形成的矿物Aka-T40,Aka-T70,Gth-T70具有颗粒均一、结晶型较好、比表面积较大等特性,是良好的去除环境污染物的吸附剂材料。

In the present work, based on the stable phase of α-FeOOH and β-FeOOH easily formed in ferric solutions of Fe （NO3）3 and FeC13 at the appropriate pH values, respectively, the phase and erystallizability, morphologies and sizes for the par- ticles of FeOOH minerals prepared under the conditions of heating at 40 and 70℃, and magnetic stirring at 25 ℃ were identified and examined by X-ray diffraction （XRD）, transmission/scanning electron microscopy （TEM/SEM） and laser scattering particle analyzer. Meanwhile the surface chemistry properties were also detected and analyzed by Fourier transform infrared spectrometer （FTIR）. Investigation results showed that the prepared minerals Gth-TT0 （α-FeOOH）, Aka-T40 and Aka-TT0 （β-FeOOH） have good properties of nanocrystallity, homogeneous particles and higher specific surface areas, which induced that the above α,β-FeOOH are potentially excellent adsorbent materials for removal of some contaminants in circumstances.