Castilla-Amorós Laia, Stoian Dragos, Pankhurst James R, Varandili Seyedeh Behnaz, Buonsanti Raffaella
Laboratory of Nanochemistry for Energy (LNCE), Department of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne, CH-1950 Sion, Switzerland.
J Am Chem Soc. 2020 Nov 11;142(45):19283-19290. doi: 10.1021/jacs.0c09458. Epub 2020 Nov 2.
Micron/nanosized particles of liquid metals possess intriguing properties and are gaining popularity for applications in various research fields. Nevertheless, the knowledge of their chemistry is still very limited compared to that of other classes of materials. In this work, we explore the reactivity of Ga nanoparticles (NPs) toward a copper molecular precursor to synthesize bimetallic Cu-Ga NPs. Anisotropic Cu-Ga nanodimers, where the two segregated domains of the constituent metals share an interface, form as the reaction product. Through a series of careful experiments, we demonstrate that a galvanic replacement reaction (GRR) between the Ga seeds and a copper-amine complex takes place. We attribute the final morphology of the bimetallic NPs, which is unusual for a GRR, to the presence of the native oxide shell around the Ga NPs and their liquid nature, via a mechanism that resembles the adhesion of bulk Ga drops to solid conductors. On the basis of this new knowledge, we also demonstrate that sequential GRRs to include more metal domains are possible. This study illustrates a new approach to the synthesis of Ga-based metal nanoparticles and provides the basis for its extension to many more systems with increased levels of complexity.
微米/纳米级液态金属颗粒具有引人入胜的特性，并且在各个研究领域的应用中越来越受欢迎。然而，与其他类别的材料相比，人们对其化学性质的了解仍然非常有限。在这项工作中，我们探索了镓纳米颗粒（NPs）与铜分子前驱体的反应性，以合成双金属铜-镓纳米颗粒。作为反应产物，形成了各向异性的铜-镓纳米二聚体，其中组成金属的两个分离域共享一个界面。通过一系列细致的实验，我们证明了镓籽晶与铜-胺配合物之间发生了电化置换反应（GRR）。我们将双金属纳米颗粒的最终形态（这对于GRR来说是不寻常的）归因于镓纳米颗粒周围天然氧化壳的存在及其液态性质，其机制类似于块状镓滴与固体导体的粘附。基于这一新知识，我们还证明了进行连续GRR以纳入更多金属域是可行的。这项研究阐述了一种合成镓基金属纳米颗粒的新方法，并为将其扩展到更多更复杂的体系提供了基础。
