In collaboration with colleagues, MIT researchers have unveiled a method to control nanoparticles’ size, composition, and other properties precisely, which are critical to various clean energy and environmental technologies. This breakthrough was achieved by leveraging ion irradiation, a technique involving beams of charged particles bombarding a material.
The researchers demonstrated that nanoparticles produced through this method exhibit superior performance compared to their conventionally made counterparts. These nanoparticles hold significance in fuel and electrolysis cells, key components of clean energy technologies.
Fuel and electrolysis cells rely on electrochemical reactions involving electrodes coated with catalysts to accelerate reactions. A common challenge faced is the durability of metal-oxide catalysts due to coarsening at high temperatures. The researchers explored metal exsolution, a process where metal nanoparticles precipitate out of a host oxide onto the electrode’s surface, enhancing stability.
Controlling the properties of resulting nanoparticles has been challenging. The researchers, led by Professor Bilge Yildiz, discovered that ion irradiation could provide the necessary control. By aiming an ion beam at the electrode while simultaneously exsolving metal nanoparticles onto the surface, they could precisely engineer the nanoparticles’ size, composition, density, and location.
The ion irradiation method allowed the creation of nanoparticles significantly smaller than those produced through conventional methods. Additionally, the researchers could change the composition of the nanoparticles by irradiating them with specific elements, showcasing a direct way to engineer composition.
The team found ion irradiation-induced defects in the electrode, providing additional nucleation sites for the nanoparticles and increasing their density. This technique also offers the potential for extreme spatial control over the nanoparticles, paving the way for well-controlled micro- and nanostructures.
The nanoparticles created using ion irradiation demonstrated superior catalytic activity than those produced through conventional thermal exsolution alone. The researchers believe that this advancement could contribute to technologies such as fuel cells for CO2-free electricity generation and the production of clean hydrogen feedstocks through electrolysis cells.
The research was funded by OxEon Corp. and MIT’s Plasma Science and Fusion Center. The study, showcasing the potential of ion irradiation in nanoparticle engineering, could have far-reaching implications for advancing clean energy and environmental technologies.
