Etching-Assisted Route to Heterophase Au Nanowires with Multiple Types of Active Surface Sites for Silane Oxidation

作者：Chaoqi Wang, Xiang Li, Lei Jin, Penghan Lu, Catherine Dejoie, Wenxin Zhu, Zhenni Wang, Wei Bi, Rafal E. Dunin-Borkowski, Kai Chen,* and Mingshang Jin*

杂志：Nano Letters, 2019, XXXX, XXX, XXX-XXX

链接：https://pubs.acs.org/doi/abs/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.

         金明尚教授课题组主要从事的是金属纳米材料的结构调控和功能化研究，主要包括金属纳米颗粒的结构调控、催化性能研究、金属复合催化剂制备等。欢迎相关院系的学生报考。近年来金明尚课题组在金属纳米材料合成和催化方面已发表系列工作：ChemSusChem, 2013, 6, 1883-1887; J. Mater. Chem. A, 2013, 1, 7316-7320; J. Mater. Chem. A, 2014, 2, 902-906; Nanoscale, 2014, 6, 3518-3521; Chem. Sci., 2015, 6, 5197-5203; ACS Nano, 2015, 9, 3307-3313; ACS Nano, 2016, 10, 4559-4564; J. Mater. Chem. A, 2016, 4, 13033-13039; Nano Lett., 2016, 16, 5669-5674; ACS Nano, 2017, 11, 163-170; J. Mater. Chem. A, 2017, 5, 10150-10153; Mater. Horiz., 2017, 4, 584-590; Nat. Commun., 2017, 8, 1261；Nano Lett., 2019, 19, 1743-1748等。