High‐entropy alloy nanoparticles (HEA NPs) have attracted significant interest due to their multielement interactions and high surface areas, making them promising candidates for heterogeneous catalysis. Their broader implementation, however, is often limited by restrictive synthesis conditions and challenges in scalable production. Laser‐based strategies have recently emerged as versatile, green approaches enabling the preparation of colloidal, support‐free HEA NPs under ambient conditions. Pulsed laser techniques exploit ultrafast heating and rapid quenching in liquids, affording kinetic control that promotes single‐phase formation with homogeneous elemental distributions. Some approaches also offer significant potential for scale‐up and high‐throughput production, as well as access to amorphous HEA NPs. This focused review summarizes and critically compares recent advances in laser‐based fabrication of HEA NPs in the liquid phase, focusing on laser reduction in liquid, laser ablation in liquid, and microparticle laser fragmentation in liquid. We highlight advantages and limitations with respect to I) compositional flexibility, II) nanoparticle size, phase structure and elemental composition, and III) convenience and scalability of the method. Finally, emerging applications of laser‐synthesized HEA NPs in heterogeneous catalysis and magnetism are highlighted, underscoring the need for further developments toward fundamental understanding, large‐scale production, and practical deployment.
Stuckert et al. (Fri,) studied this question.