Ringe Emilie
Department of Materials Science and Metallurgy, Department of Earth Sciences, University of Cambridge, Cambridge, United Kingdom CB2 3EQ.
J Phys Chem C Nanomater Interfaces. 2020 Jul 23;124(29):15665-15679. doi: 10.1021/acs.jpcc.0c03871. Epub 2020 Jun 12.
Localized surface plasmon resonances have attracted much attention due to their ability to enhance light-matter interactions and manipulate light at the subwavelength level. Recently, alternatives to the rare and expensive noble metals Ag and Au have been sought for more sustainable and large-scale plasmonic utilization. Mg supports plasmon resonances, is one of the most abundant elements in earth's crust, and is fully biocompatible, making it an attractive framework for plasmonics. This feature article first reports the hexagonal, folded, and kite-like shapes expected theoretically from a modified Wulff construction for single crystal and twinned Mg structures and describes their excellent match with experimental results. Then, the optical response of Mg nanoparticles is overviewed, highlighting Mg's ability to sustain localized surface plasmon resonances across the ultraviolet, visible, and near-infrared electromagnetic ranges. The various resonant modes of hexagons, leading to the highly localized electric field characteristic of plasmonic behavior, are presented numerically and experimentally. The evolution of these modes and the associated field from hexagons to the lower symmetry folded structures is then probed, again by matching simulations, optical, and electron spectroscopy data. Lastly, results demonstrating the opportunities and challenges related to the high chemical reactivity of Mg are discussed, including surface oxide formation and galvanic replacement as a synthetic tool for bimetallics. This Feature Article concludes with a summary of the next steps, open questions, and future directions in the field of Mg nanoplasmonics.
局域表面等离子体共振因其能够增强光与物质的相互作用并在亚波长水平上操控光而备受关注。近来,人们一直在寻找稀有且昂贵的贵金属银和金的替代物,以实现更具可持续性和大规模的等离子体应用。镁能支持等离子体共振,是地壳中含量最丰富的元素之一,并且具有完全的生物相容性,这使其成为等离子体学的一个有吸引力的框架。这篇专题文章首先报道了通过改进的伍尔夫构造理论上预期的单晶和孪晶镁结构的六边形、折叠形和风筝形,并描述了它们与实验结果的完美匹配。然后,概述了镁纳米颗粒的光学响应,突出了镁在紫外、可见和近红外电磁范围内维持局域表面等离子体共振的能力。通过数值和实验展示了六边形的各种共振模式,这些模式导致了等离子体行为高度局域化的电场特性。接着,再次通过匹配模拟、光学和电子能谱数据,探究了这些模式以及从六边形到对称性较低的折叠结构的相关场的演变。最后,讨论了与镁的高化学反应性相关的机遇和挑战的结果,包括表面氧化物的形成以及作为双金属合成工具的电化置换。这篇专题文章最后总结了镁纳米等离子体学领域的下一步、未解决的问题和未来方向。