To produce clean energy such as hydrogen more cheaply and efficiently, the key is how quickly and inexpensively high-performance catalysts can be made with minimal power. A domestic research team has proposed a solution. A team at the Korea Advanced Institute of Science and Technology (KAIST) developed a technology that creates an ultrahigh temperature of 3,000 degrees by shining light for just 0.02 seconds and rapidly and efficiently synthesizes catalysts for hydrogen production.
KAIST said on Oct. 20 that research teams led by Professor Kim Il-doo of the Department of Materials Science and Engineering and Professor Choi Seong-yul of the School of Electrical Engineering developed a synthesis platform for making high-performance nano new materials by briefly irradiating strong light, called "direct-contact photothermal annealing."
The researchers implemented a technology that emits heat of 3,000 degrees Celsius by shining strong light from a xenon lamp for just 0.02 seconds. Using the heat of this light, they succeeded in converting hard "nanodiamond" into "carbon nanoonion," which conducts electricity well and is suitable for catalysts.
A nanodiamond is, literally, a minute carbon particle with a diamond structure (with a diameter on the order of a few nanometers). It is hard and chemically stable, so it does not change easily, but because of these properties it has been difficult to convert into other materials.
A carbon nanoonion is a spherical material in which carbon atoms are stacked in multiple layers like an onion, and it has excellent electrical conductivity, making it suitable for supporting catalysts. The problem was that after making this material, a complicated process was required to attach a metal catalyst, and existing thermal annealing methods that heat with a heating wire wasted a lot of energy and took a long time.
The researchers solved these limitations with the "photothermal effect." By mixing nanodiamond with black carbon black, which absorbs light well, and flashing strong light, the nanodiamond converted into carbon nanoonion in 0.02 seconds. Computer simulations confirmed that this process is physically feasible.
The researchers also implemented catalytic functionality in this process. When metal precursors such as platinum (Pt), cobalt (Co), and nickel (Ni) are added together, the metals split into single atoms and attach one by one to the surface of the newly formed carbon nanoonion. Thanks to rapid cooling, the atoms do not agglomerate again, so material synthesis and catalyst functionalization are completed in one step.
Using this method, the team successfully synthesized eight types of high-density single-atom catalysts. Among them, the "platinum single-atom catalyst–carbon nanoonion" produced hydrogen with six times higher efficiency than before while drastically reducing the amount of platinum used.
Professor Kim said, "With an ultrafast synthesis technology that reduces energy consumption by more than 1,000 times compared with conventional thermal annealing, we expect to accelerate commercialization in several fields, including hydrogen energy as well as gas sensors and environmental catalysts."
The results were published as the inside cover paper in the September issue of ACS Nano, an international journal in the nano and chemistry fields published by the American Chemical Society (ACS).
References
ACS Nano (2025), DOI: 10.1021/acsnano.5c11229