Synthesis of metal alloy nanoparticles in solution by laser irradiation of a metal powder suspension

A simple, convenient, and general method for the synthesis of metal and metal alloy nanoparticles is presented. Irradiation of metal powders in suspension in either aqueous or organic solutions by unfocused 532 nm laser radiation produces nanoparticles with a homogeneous composition proportional to the composition of the starting metal powder mixture. This is demonstrated using UV-vis absorption spectroscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and modelization. The mechanism of alloy formation is discussed.