Muñeton Arboleda David, Coviello Vito, Palumbo Arianna, Pilot Roberto, Amendola Vincenzo
Department of Chemical Sciences, University of Padova, Padova, Italy.
Centro de Investigaciones Ópticas CIOp (CONICET-CIC-UNLP) and Facultad de Ingeniería UNLP, La Plata, Argentina.
Nanoscale Horiz. 2025 Jan 27;10(2):336-348. doi: 10.1039/d4nh00449c.
The development and understanding of alternative plasmonic materials are crucial steps for leveraging new plasmonic technologies. Although gold and silver nanostructures have been intensively studied, the promising plasmonic, chemical and physical attributes of rhodium remain poorly investigated. Here, we report the synthesis and plasmonic response of spherical Rh nanoparticles (NPs) with sizes in the 20-40 nm range. Due to the high cohesive energy of this metal, synthesis and experimental investigations of Rh nanospheres in this size range have not been reported; yet, it becomes possible here using a green and one-step laser ablation in liquid method. The localized surface plasmon (LSP) of Rh NPs falls in the ultraviolet spectral range (195-255 nm), but the absorption tail in the visible region increases significantly upon clustering of the nanospheres. The surface binding ability of Rh NPs towards thiolated molecules is equivalent to that of Au and Ag NPs, while their chemical and physical stability at high temperatures and in the presence of strong acids such as aqua regia is superior to those of Au and Ag NPs. The plasmonic features are well described by classical electrodynamics, and the results are comparable to Au and Ag NPs in terms of extinction cross-section and local field enhancement, although blue shifted. This allowed, for instance, their use as an optical nanosensor for the detection of ions of toxic metals in aqueous solution and for the surface enhanced Raman scattering of various compounds under blue light excitation. This study explores the prospects of Rh NPs in the realms of UV and visible plasmonics, while also envisaging a multitude of opportunities for other underexplored applications related to plasmon-enhanced catalysis and chiroplasmonics.
开发和了解替代等离子体材料是利用新的等离子体技术的关键步骤。尽管金和银纳米结构已得到深入研究，但铑具有前景的等离子体、化学和物理特性仍未得到充分研究。在此，我们报告了尺寸在20 - 40 nm范围内的球形铑纳米颗粒（NPs）的合成及等离子体响应。由于这种金属的高内聚能，尚未有关于该尺寸范围内铑纳米球的合成及实验研究报道；然而，在此使用绿色一步法液体激光烧蚀法使其成为可能。铑纳米颗粒的局域表面等离子体（LSP）落在紫外光谱范围（195 - 255 nm），但在纳米球聚集时，可见区域的吸收尾显著增加。铑纳米颗粒对硫醇化分子的表面结合能力与金和银纳米颗粒相当，而它们在高温及王水等强酸存在下的化学和物理稳定性优于金和银纳米颗粒。经典电动力学很好地描述了等离子体特征，尽管发生了蓝移，但在消光截面和局部场增强方面，结果与金和银纳米颗粒相当。例如，这使得它们能够用作光学纳米传感器，用于检测水溶液中有毒金属离子，并用于蓝光激发下各种化合物的表面增强拉曼散射。本研究探索了铑纳米颗粒在紫外和可见等离子体领域的前景，同时也设想了与等离子体增强催化和手性等离子体相关的其他未充分探索应用的众多机会。
