Immobilization of nanoscale Fe0 in and on PVA microspheres for nitrobenzene reduction.
Immobilization of nanoscale Fe0 in and on PVA microspheres for nitrobenzene reduction.
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DOI：
10.1016/j.jhazmat.2009.08.004
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发表时间：
2009-12
影响因子：
13.6
通讯作者：
X. Bai;Z. Ye;Yan-zhi Qu;Yan-feng Li;Zhongyou Wang
中科院分区：
文献类型：
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作者：
X. Bai;Z. Ye;Yan-zhi Qu;Yan-feng Li;Zhongyou Wang
本研究采用反相悬浮交联法将纳米FeO固定在聚乙烯醇(PVA)微球内和表面。在有无分散剂的情况下，合成了两种不同尺寸的Fe0/PVA微球。用傅立叶变换红外光谱和X射线光电子能谱分析了Fe2+与PVA的络合作用。用环境扫描电子显微镜、能量色散X-射线能谱、X-射线衍射仪对所制备的Fe0/PVA微球的形貌和分布进行了表征。纳米Fe0粒子主要分散在微球表面。与直径为10-12μm的FeO/PVA微球相比，直径为600-700μm的FeO/PVA微球表面分布更均匀，其还原反应符合准一级动力学。经测定，L-Fe0/PVA微球的归一化表面速率常数为0.162Lh−1M−2，S Fe0/PVA微球的归一化表面速率常数为0.098Lh−1M−2，纳米FeO微球的归一化表面速率常数为0.023Lh−1M−2。通过对产物的GC/MS分析，提出了Fe0/PVA微球还原Nb的可能途径。测定了大颗粒Fe0/PVA微球中铁的回收率为81.17%，小颗粒Fe0/PVA微球中铁的回收率为60.31%。
In this study, nanoscale Fe0was immobilized in and on poly(vinyl alcohol) (PVA) microspheres by the inverse suspension crosslinked method. Two different sizes of Fe0/PVA microspheres were synthesized in the presence and absence of dispersant. The chelating action between Fe2+and PVA was identified by Fourier transform infrared and X-ray photoelectron spectroscopy. The morphology and distribution of the obtained Fe0/PVA microspheres were characterized by environmental scanning electron microscope, energy-dispersive X-ray spectrometry, and X-ray diffraction. Nanoscale Fe0particles were mostly dispersed over the surface of the microspheres. They were distributed more homogeneously on the surfaces of Fe0/PVA microspheres with diameter of 600–700μm than those with diameter of 10–12μm. The nitrobenzene (NB) reduction reactions followed pseudo-first-order kinetics. The normalized surface rate constants (kSA) values were determined to be 0.162Lh−1m−2for L-Fe0/PVA microspheres, 0.098Lh−1m−2for S-Fe0/PVA microspheres, and 0.023Lh−1m−2for nanoscale Fe0particles. Furthermore, with the analysis of the products by GC/MS, possible reductive pathways of NB by Fe0/PVA microspheres were suggested. The recovery rates of iron in microspheres were determined to be 81.17% for large Fe0/PVA and 60.31% for small Fe0/PVA.