催化作用
材料科学
化学工程
纳米线
蚀刻(微加工)
硅烷
堆积
纳米技术
透射电子显微镜
各向同性腐蚀
粉末衍射
结晶学
化学
复合材料
有机化学
图层(电子)
工程类
作者
Chaoqi Wang,Xiang Li,Lei Jin,Peng-Han Lu,Catherine Dejoie,Wenxin Zhu,Zhenni Wang,Weihong Bi,Rafal E. Dunin-Borkowski,Kai Chen,Mingshang Jin
出处
期刊:Nano Letters
[American Chemical Society]
日期:2019-07-30
卷期号:19 (9): 6363-6369
被引量:18
标识
DOI:10.1021/acs.nanolett.9b02532
摘要
The construction of multiple types of active sites on the surface of a metallic catalyst can markedly enhance its catalytic activity toward specific reactions. Here, we show that heterophase gold nanowires (Au NWs) with multiple types of active surface sites can be synthesized using an etching-assisted process, yielding the highest reported turnover frequency (TOF) for Au catalysts toward the silane oxidation reaction by far. We use synchrotron powder X-ray diffraction (PXRD) and aberration-corrected (scanning) transmission electron microscopy (TEM) to show that the Au NWs contain heterophase structures, planar defects, and surface steps. Moreover, the contribution to the catalytic performance from each type of active sites was clarified. Surface steps on the Au NW catalysts, which were identified using aberration-corrected (scanning) TEM, were shown to play the most important role in enhancing the catalytic performance. By using synchrotron PXRD, it was shown that a small ratio of metastable phases within Au NWs can enhance catalytic activity by a factor of 1.35, providing a further route to improve catalytic activity. Of the three types of surface active sites, surface terminations of planar defects such as twin boundaries (TB) and stacking faults (SF) are less active than metastable phases and surface steps for Au catalysts toward the silane oxidation reaction. Such an etching-assisted synthesis of heterophase Au NWs promises to open new possibilities for catalysis, plasmonic, optics, and electrical applications.
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