Mathiesen Jette K, Ashberry Hannah M, Pokratath Rohan, Gamler Jocelyn T L, Wang Baiyu, Kirsch Andrea, Kjær Emil T S, Banerjee Soham, Jensen Kirsten M Ø, Skrabalak Sara E
Department of Chemistry and Nano-Science Center, University of Copenhagen, Universitetsparken 5, Copenhagen 2100, Denmark.
Department of Chemistry, Indiana University-Bloomington, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States.
ACS Nano. 2024 Oct 1;18(39):26937-26947. doi: 10.1021/acsnano.4c08835. Epub 2024 Sep 19.
Introducing one general synthesis to form bimetallic nanoparticles (NPs) could accelerate the discovery of NPs for promising energy applications. Although colloidal syntheses can provide precise structural and morphological control of bimetallic NPs, the complex chemical nature of multicomponent syntheses challenges the realization of such synthetic simplicity. Common synthetic issues are frequently ascribed to the variation in metal ion precursor reactivities and complex chemical interactions between the different metal surfaces and capping agents employed. However, no systematic studies have shown how these factors compete to ultimately assign the factor limiting the mixing and formation of bimetallic NPs. Here, we provide a parametric investigation of how the intrinsic standard reduction potentials () of the metal ions and cocapping agents influence the formation of bimetallic AuCu, AuPd, and PdCu NPs. Using a combination of X-ray total scattering along with transmission electron microscopy and nuclear magnetic resonance spectroscopy, we illustrate the multifunctional role of the cocapping agents through interactions with both the metal ion precursors and NP surfaces to stabilize metastable structures. Additionally, we demonstrate how system-specific side reactions and the local metal ion coordination environment can be used to selectively tune the formation kinetics, structure, and morphology of bimetallic NPs. Ultimately, these insights show that the chemical interactions rather than the intrinsic are responsible for the formation of bimetallic NPs. Broadly, these insights should aid the synthetic design of tailored multimetallic NPs.
引入一种通用的合成方法来制备双金属纳米颗粒（NPs）可以加速用于有前景的能源应用的纳米颗粒的发现。尽管胶体合成可以对双金属纳米颗粒提供精确的结构和形态控制，但多组分合成的复杂化学性质对实现这种合成的简易性提出了挑战。常见的合成问题通常归因于金属离子前驱体反应性的变化以及所使用的不同金属表面和封端剂之间复杂的化学相互作用。然而，尚无系统研究表明这些因素如何相互竞争，最终确定限制双金属纳米颗粒混合和形成的因素。在此，我们对金属离子和共封端剂的固有标准还原电位（）如何影响双金属AuCu、AuPd和PdCu纳米颗粒的形成进行了参数研究。通过结合X射线全散射以及透射电子显微镜和核磁共振光谱，我们阐明了共封端剂通过与金属离子前驱体和纳米颗粒表面相互作用来稳定亚稳结构的多功能作用。此外，我们展示了如何利用特定于系统的副反应和局部金属离子配位环境来选择性地调节双金属纳米颗粒的形成动力学、结构和形态。最终，这些见解表明，化学相互作用而非固有因素才是双金属纳米颗粒形成的原因。广泛而言，这些见解应有助于定制多金属纳米颗粒的合成设计。
