Synthesizing high-entropy alloy materials and coatings using a bilayer ice recrystallization method

High-entropy alloys (HEAs) are usually synthesized by stabilizing thermodynamically metastable structures from high temperatures. Here we present a bilayer ice recrystallization approach performed at subzero temperatures to synthesize HEA nanoparticles or aerogels with up to 11 metal elements. We found that, below 0 °C, premelted ice channels can regulate the uniform emission of metal salts and reductants to form HEA seeds. The seeds function as anti-icing agents akin to antifreeze proteins, promoting uniform element mixing and assembly at ice grain boundaries to form HEA nanoparticles or HEA aerogels. In addition, by introducing an arbitrary template, we synthesized nanometre-thick uniform HEA coatings on diverse metal or alloy nanoparticles and macroscale aerogels. The bilayer ice recrystallization method demonstrates the application of ice chemistry for the synthesis of high-entropy-based materials with hierarchical architectures. (Figure presented.)