Observing growth of metallic crystals inside liquid metal solvents

Abstract

Liquid metals are promising unconventional solvents for dissolving metals and growing their crystals. However, how the crystals grow within these metallic solvents cannot be observed easily due to the opacity of liquid metals. Using X-ray micro-computed tomography, the three-dimensional formations of crystals inside liquid metal solvents, under different conditions, are presented. In this work, we explore the use of different liquid metals solvents for growing metallic crystals, while imaging the crystals shape and sizes inside liquid metals. We use gallium-based solvents and platinum, as the solutes and demonstrate the use of liquid metals for forming metallic crystals through modulating environmental boundary effects, controlled cooling rates, and solvent selection. It is observed that the cooling rate and composition of the reaction media will influence crystals morphologies and intermetallic phases. As a proof-of-concept, we perform hydrogen evolution reaction using metallic crystals extracted from the solvents, showcasing the potential of liquid metal-based synthesis in tailoring metallic crystals properties for enhancing catalytic activity demonstrating a strategy for engineering metallic crystals in liquid metal solvents.