Synthesis and nanojoining of high entropy nanoparticles for catalysis

High entropy materials (HEMs) are a class of metal alloys consisting of four or more molar equal or near-equal elements. HEM nanomaterials have garnered significant interest due to their wide range of applications, such as electrocatalysis, welding, and brazing. Their unique multi-principle high-entropy effect allows for tailoring the alloy composition to facilitate specific electrochemical reactions. This study focuses on the synthesis of high purity HEM nanoparticles using the method of femtosecond laser ablation synthesis in liquid. The use of ultrashort energy pulses in femtosecond lasers enables uniform ablation of materials at significantly lower power levels compared to longer pulse or continuous pulse lasers. We investigate how various femtosecond laser parameters affect the morphology, phase, and other characteristics of the synthesized nanoparticles. An innovative aspect of our solution is its ability to rapidly generate multi-component nanoparticles with a high fidelity as the input multi-component target material at a significant yielding rate. Our research thus focused on a novel synthesis of high entropy alloying CuCoMn1.75NiFe0.25 nanoparticles. We explore the characterization and unique properties of the nanoparticles, and consider electrocatalytic applications, including high power density aluminum air batteries, as well as their efficacy in the oxygen reduction reaction (ORR). The findings from this study shed light on the potential of femtosecond laser ablation synthesis in liquid as a promising technique for producing high purity HEM nanoparticles.