氧化铁和羟基氧化铁纳米结构的水热法制备及其表征

利用乙二醇辅助水热法制备氧化铁的纳米结构，系统研究了Fe^3＋和OH^-的比例、乙二醇的含量、溶液浓度以及后续热处理对氧化铁纳米结构的影响，同时研究了不用形貌的氧化铁纳米结构对其磁性的影响．研究表明：当Fe^3＋和OH^-的摩尔比〉1：4时，无论有无乙二醇的加入，所得样品都为六方相的α-Fe2O3纳米颗粒；当Fe^3＋和OH^-的摩尔比〈1：4，有乙二醇辅助时，所得样品为正交相飞机状的FeOOH纳米结构；当Fe^3＋和OH^-的摩尔比〈1：4，无乙二醇辅助时，所得样品为正交相的FeOOH纳米棒．经过600℃，1h热处理后，飞机状的FeOOH和FeOOH的纳米棒都可以转化为多孔的飞机状α-Fe2O3和α-Fe2O3的纳米棒、溶液浓度的提高只会增加样品的尺寸而对其形貌没有太大的影响．形貌和尺寸不同对材料的磁性能有很大的影响．

Synthesis and Characterization of Fe2O3 and FeOOH Nanostructures Prepared by Ethylene Glycol Assisted Hydrothermal Process

Herein, Fe₂O₃ nanostructures were prepared by the ethylene glycol (EG) assisted hydrothermal process. The effects of the molar ratio of Fe ³⁺ and OH^-, the amount of EG, the concentration and subsequent annealing on the morphology and composition were investigated. Moreover, the effects of Fe₂O₃ nanostructures with different morphology and size on the magnetic properties were also investigated. The results indicate that only hexagonal -Fe₂O₃ nanoparticles can be obtained when the molar ratio of Fe ³⁺ and OH^-is less than 1:4 with or without the addition of EG; when the Fe ³⁺ and OH^- is more than 1:4, the orthorhombic airplane-like FeOOH nanostructures can be achieved with the assistance of EG; while the Fe ³⁺ and OH^-is more than 1:4, the orthorhombic FeOOH nanorods can be achieved without the assistance of EG. The airplane-like FeOOH nanostructures and FeOOH nanorods are transformed into the porous airplane-like Fe₂O₃ nanostructures and Fe₂O₃ nanorods. With the increase of the concentration, only the size of the nanostructure is enlarged and the morphology of the nanostructure is unchanged. The different size and morphology have great influence on the magnetic properties of the Fe₂O_3.