Synthesis of assembled ZnO structures by precipitation method in aqueous media
Synthesis of assembled ZnO structures by precipitation method in aqueous media
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DOI：
10.1016/j.matchemphys.2008.11.030
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发表时间：
2009-05
影响因子：
4.6
通讯作者：
S. Sepúlveda-Guzmán;B. Reeja‐Jayan;E. Rosa;A. Torres-Castro;V. González-González-V.-González-González-1399539544;M. José-Yacamán
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文献类型：
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作者：
S. Sepúlveda-Guzmán;B. Reeja‐Jayan;E. Rosa;A. Torres-Castro;V. González-González-V.-González-González-1399539544;M. José-Yacamán
在这项工作中，阵列的亚微米氧化锌结构成功地合成使用一步水相沉淀法。通过改变反应温度，得到了雪花状和花状的形貌。X射线衍射（XRD）分析表明，ZnO阵列具有纤锌矿结构。通过扫描电子显微镜（SEM），透射电子显微镜（TEM），高分辨率透射电子显微镜（HRTEM），和高角度环形暗场（HAADF）的分析的基础上，提出了一种可能的生长机制。我们的研究结果表明，ZnO阵列的生长机制是通过自聚集，并通过提高反应温度增强这种定向聚集。结果还表明，聚集过程引入了几种结构缺陷，如质量分布和晶体结构的差异。为了研究样品的表面化学组成，还用XPS对其进行了表征。结果表明，ZnO表面存在Zn（OH）2和吸附碳物种。此外，光致发光特性表明，在紫外光激发下（λ=360nm），所有样品都呈现出以390nm为中心的特征紫外发光，并且在60°C下合成的样品还观察到可见光发射。
In this work, arrays of submicron ZnO structures were successfully synthesized using a one-step aqueous precipitation method. Snowflake-like and flower-like morphologies were obtained by changing the reaction temperature. X-ray diffraction (XRD) patterns indicated that the ZnO arrays have a wurtzite crystal structure. A possible growth mechanism based on the analysis done by scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and high-angle annular dark field (HAADF) is proposed. Our findings suggest that the growth mechanism of the ZnO arrays is by self-aggregation, and that such an oriented aggregation is enhanced by increasing the reaction temperature. The results also revealed that the aggregation process introduces several structural defects such as differences in mass distribution and crystalline structure. In order to study the surface chemical composition the samples were also characterized by XPS. The results showed the presence of Zn(OH)2and absorbed carbon species on the ZnO surface. In addition, the photoluminescence characterization showed that on UV excitation (λ=360nm) all samples present the characteristic UV emission centered at 390nm, and for the sample synthesized at 60°C, a visible emission was also observed.