Shao Feng, Wang Wei, Yang Weimin, Yang Zhilin, Zhang Yao, Lan Jinggang, Dieter Schlüter A, Zenobi Renato
Department of Physics and Astronomy, National Graphene Institute, University of Manchester, Manchester, UK.
Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland.
Nat Commun. 2021 Jul 27;12(1):4557. doi: 10.1038/s41467-021-24856-5.
Plasmon-induced chemical reactions (PICRs) have recently become promising approaches for highly efficient light-chemical energy conversion. However, an in-depth understanding of their mechanisms at the nanoscale still remains challenging. Here, we present an in-situ investigation by tip-enhanced Raman spectroscopy (TERS) imaging of the plasmon-induced [4+4]-cycloaddition polymerization within anthracene-based monomer monolayers physisorbed on Au(111), and complement the experimental results with density functional theory (DFT) calculations. This two-dimensional (2D) polymerization can be flexibly triggered and manipulated by the hot carriers, and be monitored simultaneously by TERS in real time and space. TERS imaging provides direct evidence for covalent bond formation with ca. 3.7 nm spatial resolution under ambient conditions. Combined with DFT calculations, the TERS results demonstrate that the lateral polymerization on Au(111) occurs by a hot electron tunneling mechanism, and crosslinks form via a self-stimulating growth mechanism. We show that TERS is promising to be plasmon-induced nanolithography for organic 2D materials.
表面等离子体激元诱导化学反应（PICRs）最近已成为实现高效光化学能量转换的有前景的方法。然而，在纳米尺度上深入理解其机制仍然具有挑战性。在此，我们通过针尖增强拉曼光谱（TERS）成像对吸附在Au(111)上的蒽基单体单层内的表面等离子体激元诱导的[4+4]环加成聚合进行原位研究，并用密度泛函理论（DFT）计算对实验结果进行补充。这种二维（2D）聚合可以由热载流子灵活触发和操控，并通过TERS在实时和空间上同时进行监测。TERS成像在环境条件下以约3.7纳米的空间分辨率为共价键形成提供了直接证据。结合DFT计算，TERS结果表明在Au(111)上的横向聚合通过热电子隧穿机制发生，并且交联通过自刺激生长机制形成。我们表明TERS有望成为用于有机二维材料的表面等离子体激元诱导纳米光刻技术。
