A Colloidal Approach for the Synthesis of Catalytically Active Solid-Liquid-Solid Nanoparticles

Nanoreactors can synthesize highly tunable nanomaterials beyond the reach of conventional methods.. Liquid metals (LMs) have emerged as an interesting medium for materials synthesis, including nanomaterial synthesis Yet, the limited understanding of their chemistry at the nanoscale has so far hindered broader exploration. Herein, we advance the LM nanoparticle (NP) synthesis and demonstrate their use as nanoreactors to access well-defined, compositionally tunable multi-metallic NPs. We propose a colloidal approach to synthesize solid-liquid-solid core-shell-shell NPs wherein a solid metal core (Ag, Au, Cu or Pd) is embedded into a liquid Ga NP surrounded by its native oxide skin. Using state of the art characterization, we observe a core dissolution and recrystallization within the liquid Ga NP during the synthesis. We use this understanding to access novel Ag-Au nanodimers within a liquid Ga shell.Finally, we show that solid-liquid-solid NPs are promising electrocatalysts with improved structural stability over the solid core only.