Villegas Josanlet C, Giraldo Oscar H, Laubernds Kate, Suib Steven L
Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269, USA.
Inorg Chem. 2003 Sep 8;42(18):5621-31. doi: 10.1021/ic030054k.
Manganese oxide species (MnO(x)) have been intercalated within the gallery spaces of Mg-Al layered double hydroxides (LDHs). Synthesis of these materials was achieved by ion-exchange of the LDH-nitrate precursor with permanganate anion followed by reduction with organic reagents, such as glucose, ethanol, and ascorbic acid. Elemental analysis, X-ray diffraction, FT-IR spectroscopy, Raman spectroscopy, HR-TEM, and N(2) sorption analyses have been used to characterize these materials. TEM micrographs of LDH-MnO(x) materials revealed platelike morphology, characteristic of hydrotalcite-like compounds. Chemical analysis results showed that permanganate anions exchanged with nitrate anions. FT-IR and Raman spectroscopy confirmed the reduction of the permanganate anions after treatment with the organic reagents. The XRD diffraction patterns of LDH-MnO(x) revealed that the layer structure is maintained after all synthetic steps. The observed basal spacings of intercalates varied depending on the reducing agent; the largest expansion was 9.93A, corresponding to the use of ascorbic acid. The specific surface areas were also affected according to the organic reagent used, indicating that the structural modifications in the interlayer domain observed by X-ray diffraction also influence the microtextural properties.
氧化锰物种（MnO(x)）已插层于镁铝层状双氢氧化物（LDHs）的层间空间内。这些材料通过用高锰酸根阴离子对LDH-硝酸盐前体进行离子交换，随后用葡萄糖、乙醇和抗坏血酸等有机试剂还原而合成。元素分析、X射线衍射、傅里叶变换红外光谱、拉曼光谱、高分辨透射电子显微镜和N(2)吸附分析已用于表征这些材料。LDH-MnO(x)材料的透射电子显微镜图像显示出类似水滑石化合物的特征性板状形态。化学分析结果表明高锰酸根阴离子与硝酸根阴离子发生了交换。傅里叶变换红外光谱和拉曼光谱证实了用有机试剂处理后高锰酸根阴离子的还原。LDH-MnO(x)的X射线衍射图谱表明在所有合成步骤后层状结构得以保持。观察到的插层物的基面间距因还原剂而异；最大膨胀为9.93埃，对应于使用抗坏血酸的情况。比表面积也根据所使用的有机试剂而受到影响，这表明通过X射线衍射观察到的层间域的结构修饰也会影响微观结构性质。
