Underlying Mechanisms of Hot Carrier-Driven Reactivity on Bimetallic Nanostructures
Underlying Mechanisms of Hot Carrier-Driven Reactivity on Bimetallic Nanostructures
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DOI：
10.1021/acs.jpcc.1c00155
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发表时间：
2021-01-25
影响因子：
3.7
通讯作者：
Kurouski, Dmitry
中科院分区：
文献类型：
--
作者：
Li, Zhandong;Rigor, Joel;Kurouski, Dmitry
双金属纳米结构表现出独特的催化活性和选择性，这是不明显的，为他们的monoclonal类似物。这样的纳米结构包含等离子体金属，例如金或银，其提供电磁辐射的高效收集及其转化为热载流子。这些高能物质被转移到纳米结构的催化金属子组分，在那里可以催化大范围的化学反应。因此，电场的强度以及纳米尺度下催化金属和等离子体金属之间的相互作用对于纳米结构的催化活性至关重要。在这项研究中，我们调查的催化活性和局部电场之间的关系，金-钯（Au@PdNPs）和金-铂（AugPtNPs）纳米片的表面上使用尖端增强拉曼光谱。我们对这些纳米结构表面上的整流（DC）局部电场的空间变化幅度进行成像，并将其与monoclonal纳米片表面上持续的场进行比较。我们发现Au@PdNPs和AugPtNPs上的电场强度比它们的monoclonal类似物大得多。这些研究结果表明，催化效率的纳米结构可以介导和潜在的调整，通过精确控制电场持续在其表面上。
Bimetallic nanostructures exhibit unique catalytic activity and selectivity that are not evident for their monometallic analogues. Such nanostructures contain plasmonic metals, such as gold or silver, which afford highly efficient harvesting of electromagnetic radiation and its conversion into hot carriers. These highly energetic species are transferred to the catalytic metal subcomponent of the bimetallic nanostructure, where a large spectrum of chemical reactions may be catalyzed. The strength of the electric field and the interplay between catalytic and plasmonic metals at the nanoscale are thus critically important for the catalytic activity of bimetallic nanostructures. In this study, we investigate the relationship between the catalytic activity and local electric fields sustained on the surface of gold-palladium (Au@PdNPs) and gold-platinum (AugPtNPs) nanoplates using tip-enhanced Raman spectroscopy. We image the spatially varying magnitudes of rectified (DC) local electric fields on the surface of these nanostructures and compare them to the fields sustained on the surface of monometallic nanoplates. We find substantially larger electric field magnitudes on Au@PdNPs and AugPtNPs as compared to their monometallic analogues. These findings suggest that catalytic efficiency of bimetallic nanostructures may be mediated and potentially tuned through precise control of electric fields sustained on their surfaces.