Adsorption of methylene blue onto humic acid-coated Fe3O4 nanoparticles
Adsorption of methylene blue onto humic acid-coated Fe3O4 nanoparticles
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DOI：
10.1016/j.colsurfa.2012.12.056
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发表时间：
2013-10
期刊：
影响因子：
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通讯作者：
Xian Zhang;Panyue Zhang;Zhen Wu;Ling Zhang;G. Zeng;Chunjiao Zhou
中科院分区：
文献类型：
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作者：
Xian Zhang;Panyue Zhang;Zhen Wu;Ling Zhang;G. Zeng;Chunjiao Zhou
采用共沉淀法制备了胡敏酸包覆Fe 3 O 4（HA-Fe 3 O 4）纳米磁性吸附剂。TEM分析表明，球形HA-Fe 3 O 4核的平均直径约为15 nm。热重分析表明，HA-Fe 3 O 4纳米粒子中HA的含量约为50%（w/w）。HA-Fe_3 O_4纳米粒子的FIRT光谱在1604/cm和1701/cm处观察到HA的特征吸收。HA-Fe 3 O 4纳米粒子表现出典型的超顺磁性，饱和磁化强度为77 emu/g，易于用外磁场进行固液分离。将HA-Fe 3 O 4纳米粒子用于亚甲基蓝（MB）吸附，结果表明HA-Fe 3 O 4纳米粒子对MB的吸附量明显高于Fe 3 O 4纳米粒子和HA粉体。HA-Fe 3 O 4纳米粒子在pH 3-11的宽范围内保持稳定。吸附动力学符合准二级动力学方程，吸附50% MB的时间（t1/2）为7 min。HA-Fe 3 O 4纳米粒子对亚甲基蓝的吸附等温线符合Langmuir吸附方程，最大吸附量为0.291 mmol/g。饱和HA-Fe 3 O 4纳米粒子的解吸容易进行与甲醇和乙酸的混合物的体积比为9：1。
Humic acid-coated Fe3O4(HA-Fe3O4) nanoparticles as magnetic adsorbents were prepared with co-precipitation of humic acids and Fe3O4nanoparticles. TEM analysis indicated that the average diameter of the spherical HA-Fe3O4core was about 15 nm. TGA characterization showed that the HA-Fe3O4nanoparticles contained about 50% (w/w) HA. The characteristic absorption of HA at 1604/cm and 1701/cm was observed in the FIRT spectra of HA-Fe3O4nanoparticles. The HA-Fe3O4nanoparticles exhibited a typical superparamagnetic characteristic with a saturation magnetization of 77 emu/g, which resulted in an easy solid–liquid separation with an external magnet. The HA-Fe3O4nanoparticles were applied for methylene blue (MB) adsorption and results showed that the HA-Fe3O4nanoparticles possessed much higher adsorbed amount of MB than the bare Fe3O4nanoparticles and HA powders. The HA-Fe3O4nanoparticles remained stable in a broad pH range of 3–11. The adsorption kinetics can be described by a pseudo-second-order equation, and the time when 50% of the MB was adsorbed (t1/2) was 7 min. The adsorption isotherm of the HA-Fe3O4nanoparticles agreed well with Langmuir adsorption equation, and the maximum adsorbed amount of MB was 0.291 mmol/g. Desorption of the saturated HA-Fe3O4nanoparticles was easily carried out with a mixture of methanol and acetic acid with a volume ratio of 9:1.