A Critical Textural Evolution Study of Zerovalent Iron/Montmorillonite Nanosized Heterostructures Under Various Iron Loadings
A Critical Textural Evolution Study of Zerovalent Iron/Montmorillonite Nanosized Heterostructures Under Various Iron Loadings
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DOI：
10.1346/ccmn.2011.0590506
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发表时间：
2011-10
影响因子：
2.2
通讯作者：
Mingde Fan;P. Yuan;F. Bergaya;Hongping He;Tianhu Chen;Jianxi Zhu;Dong Liu
中科院分区：
文献类型：
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作者：
Mingde Fan;P. Yuan;F. Bergaya;Hongping He;Tianhu Chen;Jianxi Zhu;Dong Liu
纳米粒子与多孔基质杂化形成的异质结构由于其固有的性质，在催化、吸附、环境修复等方面具有巨大的应用潜力。本研究的目的是合成零价铁纳米粒子/蒙脱土异质结构，并研究其织构演变下不同的铁负载。通过三价铁离子浸渍蒙脱土，然后在溶液中用硼氢化钠化学还原，制备了铁纳米粒子与蒙脱土的杂化材料。这些杂化铁纳米粒子在天然铁氧化物壳层的保护下，很好地分散在蒙脱石表面，尺寸可调，抗氧化。这些异质结构下的各种Fe负载的织构演变进行了研究，使用氮物理吸附，X-射线衍射，电子显微镜和元素分析。随着Fe负载量的增加，总孔和中孔体积几乎不变;总比表面积、比表面积和比表面积以及比表面积体积减小;平均孔径增大。这些纹理的变化可以归因于填充蒙脱石的颗粒间的孔隙由一个变量的铁纳米粒子。此外，随着Fe负载量的增加，这些异质结构的介孔特性增强。这些基本结果对于理解这些异质结构的结构以及在相关领域中开发一些新的应用具有重要意义。
Heterostructures formed by nanoparticles hybridized with porous hosts are of great potential in many practical applications such as catalysis, adsorption, and environmental remediation, based on their intrinsic properties. The objectives of this study were to synthesize zerovalent iron nanoparticles/montmorillonite heterostructures and to investigate their textural evolution under different Fe loadings. Iron nanoparticles were hybridized with montmorillonite by impregnation of montmorillonite by ferric ions followed by chemical reduction with sodium borohydride in solution. These hybridized Fe nanoparticles were well dispersed on the montmorillonite surface, size adjustable, and resistant to oxidation under the protection of native Fe-oxide shells. The textural evolution of these heterostructures under various Fe loadings was investigated using nitrogen physisorption, X-ray diffraction, electron microscopy, and elemental analyses. As the Fe loadings increased, the total pore and mesopore volumes were almost unchanged; the total, micropore, and external surface areas as well as the micropore volume decreased; and the average pore diameter increased. These textural changes could be attributed to the filling of the interparticle pores of montmorillonite by a variable amount of Fe nanoparticles. In addition, with increasing Fe loadings, the mesoporous character was enhanced for these heterostructures. These fundamental results are important in understanding the structure of these heterostructures as well as in developing some novel applications in related fields.