三氧化二铁纳米管的合成及对镉的吸附研究

Synthesis of Ferric Oxide Nanotubes and Their Adsorption to Cadmium

文章制备了纳米管状结构的α相三氧化二铁(α-Fe_2O_3),并研究其对水体中重金属镉的吸附性能。扫描电子显微镜(SEM)和X射线衍射仪(XRD)表征结果显示成功制备出结构均匀的α-Fe_2O_3纳米管,直径大约30 nm,管长在50 nm至400 nm。对水体中镉的吸附研究中,考察了溶液p H、α-Fe_2O_3投加量和镉初始浓度等对吸附效率的影响。结果表明,碱性环境中,Fe_2O_3纳米管对Cd2+的吸附效果较好,最佳p H为8。镉的去除效率随着α-Fe_2O_3纳米管投加量增加而增大,当镉的初始浓度为5000μg/L,投加量为1 g/L时,去除率可达98.9%,Fe_2O_3纳米管对Cd2+吸附符合准二级动力学模型。研究表明该氧化铁纳米管是良好的吸附材料,可用于大规模水体污染的治理和修复或地表水体的深度处理。

Ferric oxide （α-Fe2O3） with nanotube structure was prepared in the article, and then studied its adsorption properties to heavy metal Cadmium. The characterization results by scanning electron microscopy （SEM） and X-ray diffraction （XRD） show α-Fe2O3 nanotubes with uniform structure were prepared successfully. The diameter of particles is about 30 nln and length distribution is in the range of 50 nm to 400 nm. The experiences of studying adsorption to cadmium investigated the effection of pH value, α-Fe2O3 dosage and initial concentration of cadmium to adsorption efficiency. The results show that α-Fe2O3 nanotubes adsorb Cd2＋ well in alkaline environment conditions, especially in pH 8. Cadmium removal efficiency increases with the augmentation of α-Fe2O3 nanotubes dosage. When the initial concentration of cadmium was 5000 μg/L, the α-Fe2O3 nanotubes dosage is 1 g/L, the removal rate reach at 98.9 %. Meanwhile, Fe2O3 nanotubes adsorbing Cd2＋ matched well with second order kinetic model. The studies show that the iron oxide nanotuhes can be used in large-scale water pollution control and repair for their good adsorption properties.