Direct Growth of Freestanding ZnO Tetrapod Networks for Multifunctional Applications in Photocatalysis, UV Photodetection, and Gas Sensing
Direct Growth of Freestanding ZnO Tetrapod Networks for Multifunctional Applications in Photocatalysis, UV Photodetection, and Gas Sensing
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DOI：
10.1021/acsami.5b02816
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发表时间：
2015-07-08
影响因子：
9.5
通讯作者：
Adelung, Rainer
中科院分区：
文献类型：
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作者：
Mishra, Yogendra Kumar;Modi, Gaurav;Adelung, Rainer
具有复杂形态的独立纳米结构和微米结构的生长是纳米材料在各种技术中的真实的应用的高度期望的方面。从技术应用的观点来看，表现出三维（3D）形状的氧化锌四脚体（ZnO-T）是非常重要的，因此需要用于生长不同种类的基于四脚体的网络的有效技术。在这里，我们展示了一个简单的火焰传输合成（FTS）的方法，形成一个网络的多功能和单步合成的ZnO-T与不同的臂形态。通过扫描电子显微镜、X射线衍射和显微拉曼光谱测量，详细研究了这些四足体的形态演化和结构完整性。为了更深入地了解结晶度，详细的高分辨率透射电子显微镜研究的一个典型的氧化锌四脚结构。所涉及的生长机制与各种臂形态的ZnO四脚体进行了讨论相对于实验条件的变化。这些ZnO-T已被用于光催化降解和纳米传感应用。以亚甲基蓝（MB）溶液为实验对象，研究了不同臂形貌的ZnO-T纳米粒子在室温下的光催化脱色性能。结果表明，所制备的ZnO-T对亚甲基蓝具有很强的光催化活性，且在很短的时间内即可完全降解。在另一个应用中，已经从这些ZnO-T互连网络构建了纳米电子传感器件的原型，并相应地用于UV检测和H-2气体传感。所制备的器件结构表现出良好的传感性能，具有良好的实际应用前景。所涉及的传感机制，相对于紫外光子和氢气进行了详细讨论。我们认为，这种基于ZnO四脚互联网络的多功能纳米器件将是各种先进应用的兴趣。
Growth of freestanding nano- and microstructures with complex morphologies is a highly desired aspect for real applications of nanoscale materials in various technologies. Zinc oxide tetrapods (ZnO-T), which exhibit three-dimensional (3D) shapes, are of major importance from a technological applications point of view, and thus efficient techniques for growth of different varieties of tetrapod-based networks are demanded. Here, we demonstrate the versatile and single-step synthesis of ZnO-T with different arm morphologies by a simple flame transport synthesis (FTS) approach, forming a network. Morphological evolutions and structural intactness of these tetrapods have been investigated in detail by scanning electron microscopy, X-ray diffraction, and micro-Raman measurements. For a deeper understanding of the crystallinity, detailed high-resolution transmission electron microscopic studies on a typical ZnO tetrapod structure are presented. The involved growth mechanism for ZnO tetrapods with various arm morphologies is discussed with respect to variations in experimental conditions. These ZnO-T have been utilized for photocatalytic degradation and nanosensing applications. The photocatalytic activities of these ZnO-T with different arm morphologies forming networks have been investigated through the photocatalytic decolorization of a methylene blue (MB) solution under UV light illumination at ambient temperature. The results show that these ZnO-T exhibit strong photocatalytic activities against MB and its complete degradation can be achieved in very short time. In another application, a prototype of nanoelectronic sensing device has been built from these ZnO-T interconnected networks and accordingly utilized for UV detection and H-2 gas sensing. The fabricated device structures showed excellent sensing behaviors for promising practical applications. The involved sensing mechanisms with respect to UV photons and H2 gas are discussed in detail. We consider that such multifunctional nanodevices based on ZnO tetrapod interconnected networks will be of interest for various advanced applications.