Chemical Transformations in Ultrathin Chalcogenide Nanowires
Chemical Transformations in Ultrathin Chalcogenide Nanowires
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DOI：
10.1021/nn9018575
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发表时间：
2010-04-01
期刊：
影响因子：
17.1
通讯作者：
Jeong, Unyong
中科院分区：
文献类型：
--
作者：
Moon, Geon Dae;Ko, Sungwook;Jeong, Unyong
我们研究了超薄硫系纳米线的化学转变，目的是了解控制产品形态和晶体结构的参数。将超薄Te纳米线转化为Ag(2)Te纳米线，保持了单晶度。利用阳离子交换反应将Ag(2)Te纳米线转化为CdTe、ZnTe和PbTe，将CdTe纳米线进一步转化为PtTe(2)纳米管。根据离子固体的溶解度产物、所涉及的固体的晶体结构、反应动力学和转化的反应条件，我们可以得出以下结论：(1)离子固体的溶解度产物可以作为预测转化是否在热力学上有利的粗略标准。（ii）除了反应物和生成物纳米线之间的晶格匹配外，反应物纳米线的形态保存对长度的变化比总体积的变化更敏感。（iii）由转变产生的晶体结构应由形成的自由能和产物的稳定性决定。（iv）在纳米线的整个长度上，涉及小体积变化或拓扑晶格匹配的转变被认为是均匀的，既保留了单晶性，又保留了反应物纳米线的形态。
We have studied the chemical transformations in ultrathin chalcogenide nanowires with an aim to understand the parameters that control the morphology and crystal structure of the product. Ultrathin Te nanowires were transformed into Ag(2)Te nanowires with preservation of the single crystallinity. The Ag(2)Te nanowires were then converted into CdTe, ZnTe, and PbTe using cation-exchange reactions, and the CdTe nanowires were further transformed into PtTe(2) nanotubes. On the basis of the solubility products of the ionic solids, the crystal structures of the involved solids, the reaction kinetics, and the reaction conditions for transformations, we were able to reach the following conclusions: (i) The solubility products of ionic solids can be used as a rough criterion to predict if the transformation is thermodynamically favorable or not. (ii) The morphological preservation of reactant nanowires is more sensitive to the change in length rather than the total volume in addition to the lattice matching between the reactant and product nanowires. (iii) The crystal structure resulting from a transformation should be determined by the free energy of formation and the stability of the products. (iv) The transformation involving small volume change or topotactic lattice matching is considered homogeneous along the entire length of the nanowires, preserving both the single crystallinity and the morphology of the reactant nanowires.