Continuous synthesis of hedgehog-like Ag–ZnO nanoparticles in a two-stage microfluidic system
Continuous synthesis of hedgehog-like Ag–ZnO nanoparticles in a two-stage microfluidic system
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DOI：
10.1039/c6ra06101j
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发表时间：
2016-05
期刊：
影响因子：
3.9
通讯作者：
T. Sha;Mei Yang;Hui-Yu Chen;Mingyue Ren;Guangwen Chen
中科院分区：
文献类型：
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作者：
T. Sha;Mei Yang;Hui-Yu Chen;Mingyue Ren;Guangwen Chen
在连续两级微流控系统中成功制备了刺猬状Ag-ZnO纳米颗粒（NPs）。第一阶段是在柠檬酸三钠、过氧化氢和十二烷基硫酸钠的存在下，用NaBH 4还原AgNO 3，合成单分散的三角形Ag纳米棱柱。第二阶段是Zn（OH）2纳米棒在三角形Ag纳米柱上生长形成刺猬状。最后通过热分解所制备的刺猬状Ag-Zn（OH）2纳米粒子得到刺猬状Ag-ZnO纳米粒子。采用X射线衍射、透射电子显微镜和X射线光电子能谱对样品的结构、形貌和化学状态进行了表征。结果表明，H2 O2、NaOH与Zn（NO3）2的摩尔比以及AgNO 3与Zn（NO3）2的流量比对制备刺猬状Ag-ZnO纳米粒子起着至关重要的作用。此外，还考察了刺猬状Ag-ZnO纳米粒子对橙子的光催化降解活性。结果表明，与纯ZnO和球形Ag-ZnO纳米粒子相比，刺猬状Ag-ZnO纳米粒子的光催化活性得到了显著提高。反应速率常数的刺猬状的银-氧化锌纳米粒子的值是纯氧化锌的值的12倍，球形的银-氧化锌纳米粒子的值的两倍。
Hedgehog-like Ag–ZnO nanoparticles (NPs) were successfully prepared in a continuous two-stage microfluidic system. The first stage was the synthesis of monodispersed triangular Ag nanoprisms by the reduction of AgNO3 with NaBH4 in the presence of trisodium citrate, H2O2 and sodium dodecyl sulfate. The second stage was the growth of Zn(OH)2 nanorods on triangular Ag nanoprisms to form a hedgehog-like shape. Hedgehog-like Ag–ZnO NPs were finally obtained by the thermal decomposition of as-prepared hedgehog-like Ag–Zn(OH)2 NPs. The structure, morphology and chemical state of the obtained samples were characterized by X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy. It was found that H2O2, the molar ratio of NaOH to Zn(NO3)2 and the flow rate ratio of AgNO3 to Zn(NO3)2 played a crucial role in the preparation of hedgehog-like Ag–ZnO NPs. In addition, the photocatalytic activity of hedgehog-like Ag–ZnO NPs was evaluated in the degradation of methyl orange. The results showed that the photocatalytic activity was greatly enhanced by hedgehog-like Ag–ZnO NPs in comparison to pure ZnO and spherical-like Ag–ZnO NPs. The reaction rate constant of the hedgehog-like Ag–ZnO NPs was twelve times the value of pure ZnO and twice the value of spherical-like Ag–ZnO NPs.