Method Development for the Synthesis of Colloidal Multimetallic Nanocrystals

• Applicant: Guillermo González-Rubio, Ph.D.
• Subject Area: Solid State and Surface Chemistry, Material Synthesis ; Synthesis and Properties of Functional Materials ; Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry
• Term: from 2021 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 460932591

Colloidal metal nanocrystals (NCs) are unique materials with appealing physical-chemical properties which are the focus of intense research for the development of novel and green technologies with implications in solar energy-harvesting, electrocatalysis or biomedicine. Nevertheless, the practical implementation of metal NCs still presents significant issues related, for instance, to the high cost for noble metals or chemical stability of metals such as Co, Ni or Fe. Significant efforts have been dedicated to tackling such drawbacks, being the synthesis of multimetallic NCs (MM NC) one of the most promising strategies. This fact can be explained by the enhanced chemical stability and improved electrical, optical, magnetic and catalytic properties (while reducing noble-metal loading) displayed by MM NCs.Among the available fabrication routes for MM NCs colloidal chemistry methods provide unparalleled control over the size and shape of bimetallic noble-metal-based MM NCs. Unfortunately, the synthesis of non-noble MM NCs by colloidal methods remains challenging because of the large redox potential differences between distinct metals that often impair their co-crystallization. Indeed, MM NCs containing several different noble and non-noble metals are habitually synthesized through high-temperature-based methods. Nevertheless, these approaches typically possess low control over the size dispersity of the NCs, as they strongly depend on the use of supports to avoid the NC coalescence.In this DFG proposal, we aim at the development of an advanced route to synthesize colloidal MM NCs with tuneable size, morphology, composition and metal atom mixing. The fundament of the proposed strategy relies on combining the ability of colloidal methods to provide low size dispersity NCs with that of high-temperature approaches to produce MM NCs. Thereby, the envisaged approach takes roots in the vast amount of colloidal chemistry methods that have been developed in the last two decades for the synthesis of high-quality metal NCs with different dimensions and morphologies. Similarly, we will take advantage of available techniques for the assembly of colloidal NCs into MM supraparticles (i.e., particles composed of smaller particulate), which will serve as platforms for the formation of the targeted MM NCs. Ultrafast pulsed lasers will be then used for the formation of MM NCs through a laser-induced melting process of the assembled supraparticles. The proposed strategy should eventually provide access to the synthesis of a wide variety of colloidal MM NCs with different dimensions, compositions and metal atom mixing patterns.

• DFG Programme: Research Grants
• International Connection: Belgium, Spain
• Cooperation Partners: Professorin Dr. Sara Bals; Dr. Pablo Llombart; Dr. Ovidio Peña-Rodríguez; Dr. Antonio Rivera