Renard David, Tian Shu, Lou Minhan, Neumann Oara, Yang Jian, Bayles Aaron, Solti David, Nordlander Peter, Halas Naomi J
Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States.
Laboratory for Nanophotonics, Rice University, 6100 Main Street, Houston, Texas 77005, United States.
Nano Lett. 2021 Jan 13;21(1):536-542. doi: 10.1021/acs.nanolett.0c04020. Epub 2020 Dec 3.
The field of plasmonics has largely been inspired by the properties of Au and Ag nanoparticles, leading to applications in sensing, photocatalysis, nanomedicine, and solar water treatment. Recently the quest for new plasmonic materials has focused on earth-abundant elements, where aluminum is a sustainable, low-cost potential alternative. Here we report the chemical synthesis of sub-50 nm diameter Al nanocrystals with a plasmon-resonant absorption in the UV region of the spectrum. We observe a transition from a UV-resonant response, that is, a colorless solution, to a broadband absorptive response, that is, a completely black solution, as the nanocrystal concentration is increased. The strong absorptive interband transition in Al provides the dominant mechanism responsible for this effect. We developed a robust method to functionalize Al nanocrystals with silica to increase their stability in HO from hours to weeks enabling us to observe efficient broadband photothermal heating with these nanoparticles.
等离激元学领域很大程度上受到金和银纳米颗粒特性的启发，从而在传感、光催化、纳米医学和太阳能水处理等方面得到应用。最近，对新型等离激元材料的探索聚焦于储量丰富的元素，其中铝是一种可持续、低成本的潜在替代材料。在此，我们报告了直径小于50 nm的铝纳米晶体的化学合成，其在光谱的紫外区域具有等离激元共振吸收。随着纳米晶体浓度的增加，我们观察到从紫外共振响应（即无色溶液）到宽带吸收响应（即完全黑色的溶液）的转变。铝中强烈的吸收性带间跃迁是造成这种效应的主要机制。我们开发了一种用二氧化硅对铝纳米晶体进行功能化的稳健方法，以将它们在水中的稳定性从数小时提高到数周，从而使我们能够观察到这些纳米颗粒产生的高效宽带光热加热。
