High-entropy nanoalloys (HENA) have widespread applications in materials science and applied physics. However, their synthesis is challenging due to slow kinetics that cause phase segregation, sophisticated pretreatment of precursors, and inert conditions. In a new report now published in Science Advances, Haoqing Jiang and a team of scientists in industrial engineering, nanotechnology and materials science in the U.S., and China, described a process of converting metal salts to ultrafine HENAs on carbonaceous supports using nanosecond pulse lasers. Based on the unique laser induced thermionic emission and etch on carbon, the team gathered the reduced metal elements of ultrafine HENAs stabilized via the defective carbon support. The resulting process produced a variety of HENAs ranging from 1-to-3 nanometers and metal elements of up to 11 grams per hour, with a productivity reaching 7 grams per hour. The HENAs exhibited excellent catalytic performance during oxygen reduction, with great practical potential.