This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Nitrogen dioxide is a harmful gas that requires sensitive detection. Researchers used intense light pulses lasting 10 milliseconds to make molybdenum disulfide flakes and anchor isolated metal atoms in one step.
Adding platinum improved the material's room-temperature response to nitrogen dioxide, reaching 100.8% at 400 parts per billion and a detection limit of 17.2 parts per billion. This approach could support advanced gas sensors and applications in catalysis and energy technologies. Many gas sensors detect gases through changes in a material's electrical properties.
Molybdenum disulfide (MoS₂) is promising, but much of its surface is inactive. Its more reactive edges can be difficult to preserve during conventional heating, while added catalyst metals may clump together instead of remaining as individual atoms. The research was jointly led by Professor Il-Doo Kim from Korea Advanced Institute of Science and Technology (KAIST) and Assistant Professor Dong-Ha Kim from Hanyang University-ERICA as co-corresponding authors, with Dr.
Euichul Shin from KAIST serving as the first author. They used flash thermal synthesis, driven by intense pulsed light, to turn a molybdenum-containing precursor into thin MoS₂ flakes. A single 10-millisecond pulse heated the material to as high as 1,811°C, then cooled it rapidly in ambient air.
Platinum, iridium or gold atoms could be incorporated during the same step. The paper is published in the journal Advanced Materials. The brief, intense heating helped limit the growth of large flakes and kept the added metal atoms dispersed across the material rather than forming agglomerated metal nanoparticles.
In tests, the flash-made MoS₂ produced a 23.6-fold stronger response to 5 parts per million of nitrogen dioxide (NO₂) than material made by a conventional solvothermal method. Adding 1.2 weight% platinum boosted response 22.8-fold: the sensor response reached 100.8% when exposed to 400 parts per billion of NO₂ at room temperature. "The important advance is that we can form the sensing material and add isolated catalyst atoms in one rapid step, without needing a prolonged furnace treatment," said Kim.
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