Morphology control of cryptomelane type MnO2 nanowires by soft chemistry. growth mechanisms in aqueous medium
Morphology control of cryptomelane type MnO2 nanowires by soft chemistry. growth mechanisms in aqueous medium
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DOI：
10.1021/cm071654a
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发表时间：
2007-10-30
影响因子：
8.6
通讯作者：
Jolivet, Jean-Pierre
中科院分区：
文献类型：
--
作者：
Portehault, David;Cassaignon, Sophie;Jolivet, Jean-Pierre
采用反应4)法在60℃和95℃的温度下合成了一维锰氧化物(隐锰酸钾)纳米线，并用粉末X射线衍射、电子显微镜、氮气吸附-脱附等手段对其进行了低温表征。开发了两种合成方法，取决于初始pH是调节还是始终固定在固相形成过程中。这两种方法都显示出纳米线的形貌随直径、长度和比表面积的变化，分别在15-40 nm、0.1-1.1微米和35-110米(2)中心点g(-1)范围内变化，这取决于生长条件(酸度和温度)。结果表明，纳米线的生长机制为横向定向附着一次10 nm宽的纳米棒，纵向为溶解-结晶。用初级纳米棒之间的静电相互作用解释了直径随酸性条件的变化。
Nanowires of one-dimensional manganese oxide (cryptomelane) have been synthesized using reaction 4) route at 60 degrees C and 95 degrees C. between Mn-II (MnSO4 and Mn-VII (KMnO4) in water by a low-temperature Characterization of the nanoparticles was carried out using powder X-ray diffraction, transmission electron microscopy electron diffraction, and nitrogen adsorption-desorption. Two synthesis methods were developed depending whether the pH was initially adjusted or fixed all along the solid formation. Both methods exhibited variation of the nanowire morphology with diameter, length, and specific area varying in the 15-40 nm, 0.1-1.1 mu m, and 35-110 m(2)center dot g(-1) ranges, respectively, depending on the growth conditions (acidity and temperature). The growth mechanism of the nanowires was proved to proceed by oriented attachment of primary 10 nm width nanorods for the lateral direction and dissolution-crystallization for the longitudinal direction. The diameter variation with acidic conditions was interpreted in terms of electrostatic interactions between primary nanorods.