Colloidal synthesis of high entropy alloy and multimetallic nanocrystals

Engineering colloidally stable multimetallic nanocrystals has many benefits in a wide range of applications and introduces the opportunity of manipulating physical, chemical, and electronic structure properties of materials at the nanoscale. Synthesis routes are challenged by the chemical complexity required to temporally and spatially coordinate the reduction and alloying of multiple metal species, which hampered the development of tunable libraries of colloidal materials to date. In this work, we demonstrate a synthesis method guided by machine learning-accelerated simulations to incorporate five or more metal elements in monodisperse, colloidally stable nanocrystals. Multiple seed materials can be used, leading to a library of multimetallic nanocrystals with tunable electronic, physical, and alloying structure. The advantage of this synthetic protocol is highlighted in the preparation of catalytic materials that showed two orders of magnitude higher reaction rates than monometallic catalysts and outstanding thermal stability, thus highlighting the promise of this approach for high-performance materials in many areas.