State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Faculty of Chemical, Environmental, and Biological Science and Technology, Dalian University of Technology, Dalian 116024, PR China.
Small. 2013 Nov 25;9(22):3852-7. doi: 10.1002/smll.201300276. Epub 2013 Jun 10.
Magnetic hollow structures with microporous shell and highly dispersed active cores (Fe/Fe3 C nanoparticles) are rationally designed and fabricated by solution-phase switchable transport of active iron species combined with a solid-state thermolysis technique, thus allowing selective encapsulation of functional Fe/Fe3 C nanoparticles in the interior cavity. These engineered functional materials show high loading (≈54 wt%) of Fe, excellent chromium removal capability (100 mg g(-1)), fast adsorption rate (8766 mL mg(-1) h(-1)), and easy magnetic separation property (63.25 emu g(-1)). During the adsorption process, the internal highly dispersed Fe/Fe3 C nanoparticles supply a driving force for facilitating Cr(VI) diffusion inward, thus improving the adsorption rate and the adsorption capacity. At the same time, the external microporous carbon shell can also efficiently trap guest Cr(VI) ions and protect Fe/Fe3 C nanoparticles from corrosion and subsequent leaching problems.
具有微孔壳和高度分散的活性核（Fe/Fe3C 纳米粒子）的磁性中空结构是通过活性铁物种的溶液相可切换传输与固态热解技术相结合来合理设计和制造的，从而可以选择性地将功能性 Fe/Fe3C 纳米粒子封装在内部腔室中。这些工程化的功能材料显示出高负载量（≈54wt%）的 Fe、优异的铬去除能力（100mg g-1）、快速的吸附速率（8766mLmg-1h-1）和易于磁分离的特性（63.25emu g-1）。在吸附过程中，内部高度分散的 Fe/Fe3C 纳米粒子提供了促进 Cr(VI)向内扩散的驱动力，从而提高了吸附速率和吸附容量。同时，外部的微孔碳壳也可以有效地捕获客体 Cr(VI)离子，并防止 Fe/Fe3C 纳米粒子受到腐蚀和随后的浸出问题。
