Amalgamation Synthesis of Intermetallic Nanocrystals

Bimetallic compounds are a vast family of materials with &gt;20000 unique members and record-high performance in plasmonic, catalytic, magnetic, and energy storage applications. In strong dissonance, universal synthesis for polymetallic nanocrystals is missing, due to challenges to combine two dissimilar metals at the nanoscale. We overcome this limitation by the amalgamation reaction at the surface of nanocrystals, [1] thus unlocking up to a 1000 of new intermetallic nanocrystals with unprecedented quality for size uniformity, composition control, and phase purity. We show the universality of our amalgamation approach and achieve a row of crystalline and compositionally uniform intermetallic nanocrystals of Au-Ga, Ag-Ga, Cu-Ga, Ni-Ga, Pd-Ga, Pd-In and Pd-Zn compounds. Furthermore, we demonstrate a compositional tunability across phase diagrams (e.g., AuGa2, AuGa, Au7Ga2, and Ga-doped Au nanocrystals for the bimetallic Au-Ga system), while each phase can be prepared with accurate size control and excellent size uniformity. Our new synthetic method is simple, predictive, and generalizable, giving access to a large family of intermetallic nanocrystals with unprecedented quality and flexibility of materials design, thus unlocking a multitude of possibilities for these materials.<br/> <br/>[1] J. Clarysse, A. Moser, O. Yarema, V. Wood, and M. Yarema, Science Advances, 2021, 7, eabg1934.