Department of Chemical and Environmental Engineering, University of California, Riverside, Riverside, CA 92521, USA.
Department of Fusion Chemical Engineering, Hanyang University, Ansan, Kyeonggi-do 426-791, Republic of Korea.
Chemosphere. 2016 Feb;144:975-81. doi: 10.1016/j.chemosphere.2015.08.056. Epub 2015 Oct 1.
In this work, α-Fe2O3 nanofibers were synthesized via electrospinning and characterized to observe optimal morphological and dimensional properties towards chromate removal. The Fe2O3 nanofiber samples were tested in aqueous solutions containing chromate (CrO4(2-)) to analyze their adsorption capabilities and compare them with commercially-available Fe2O3 nanoparticles. Synthesized Fe2O3 nanofibers were observed with a variety of different average diameters, ranging from 23 to 63 nm, while having a constant average grain size at 34 nm, point zero charge at pH 7.1, and band gap at 2.2 eV. BET analysis showed an increase in specific surface area with decreasing average diameter, from 7.2 to 59.2 m(2)/g, due to the increased surface area-to-volume ratio with decreasing nanofiber size. Based on CrO4(2-) adsorption isotherms at pH 6, adsorption capacity of the Fe2O3 nanofibers increased with decreasing diameter, with the 23 nm sized nanofibers having an adsorption capacity of 90.9 mg/g, outperforming the commercially-available Fe2O3 nanoparticles by nearly 2-fold. Additionally, adsorption kinetics was also analyzed, increasing with decreasing nanofiber diameter. The enhanced performance of the nanofiber is suggested to be caused solely due to the increased surface area, in part by its size and morphology. Electrospun Fe2O3 nanofibers provide a promising solution for effective heavy metal removal through nanotechnology-integrated treatment systems.
在这项工作中，通过静电纺丝合成了α-Fe2O3 纳米纤维，并对其进行了表征，以观察其对铬酸盐去除的最佳形态和尺寸特性。将 Fe2O3 纳米纤维样品在含有铬酸盐（CrO4(2-)）的水溶液中进行测试，以分析它们的吸附能力，并将其与市售的 Fe2O3 纳米颗粒进行比较。合成的 Fe2O3 纳米纤维的平均直径有多种不同，范围从 23 到 63nm，而平均晶粒尺寸保持在 34nm，零电荷点在 pH7.1，带隙在 2.2eV。BET 分析表明，比表面积随着平均直径的减小而增加，从 7.2 到 59.2m2/g，这是由于纳米纤维尺寸减小导致的表面积与体积比增加。根据 pH6 下的 CrO4(2-)吸附等温线，Fe2O3 纳米纤维的吸附容量随着直径的减小而增加，23nm 尺寸的纳米纤维的吸附容量为 90.9mg/g，比市售的 Fe2O3 纳米颗粒高近 2 倍。此外，吸附动力学也随着纳米纤维直径的减小而增加。纳米纤维性能的增强被认为仅归因于比表面积的增加，部分原因是其尺寸和形态。静电纺丝 Fe2O3 纳米纤维为通过纳米技术集成处理系统有效去除重金属提供了一种有前途的解决方案。
