High-Quality Intermetallic Nanoparticles from Amalgams

Amalgamation is the alloying of two metals, one of which is in liquid form. While broadly applied in metallurgy or dentistry, amalgamation process is yet majorly disregarded for nanotechnology. Recently, we developed the nanoscale amalgamation reaction for the synthesis of intermetallic and alloyed nanoparticles. [1] Starting from monometallic seeds, we carry out a thermal decomposition of metal-amides to dispatch low-melting metals to the surface of nanoparticles and thus trigger a time-efficient and homogeneous alloying to bimetallic compositions. Our new synthesis is convenient and reproducible universal method for high-quality intermetallic nanoparticles, providing uniform compositions and phase purity already after a few minutes of reaction (whereas short reaction time is the key for excellent size distributions). Finally, nanoscale amalgamation gives access to unique bimetallic nanoparticles of very dissimilar metals (for example easily reducible Au, Pd or Pt with much more active Ga or Zn), which is impossible via traditional co-precipitation methods. Combining metals at the nanoscale is a powerful strategy for many applications: large surface area for efficient catalysis, size-dependent properties for ultralow-power phase-change memory and high-Q factor plasmonic applications, small diameter for effective nanomedicine or ultrafine-grain thermoelectrics and additive manufacturing are just to name a few. Our synthesis supplies high-quality intermetallic nanoparticles for this wide range of emerging applications.<br/><br/>[1] J. Clarysse, A. Moser, O. Yarema, V. Wood, and M. Yarema, Science Advances, 2021, 7, eabg1934.