A research team from Stony Brook University and Brookhaven National Laboratory has been studying argon gas, and the group’s findings have been published in Nature Communications. Argon and other noble gases have previously been trapped in three-dimensional porous materials. Prior to the SBU-BNL research, immobilizing these gases on surfaces had only been achieved by either cooling them to very low temperatures to condense them, or by accelerating gas ions to implant them directly into materials.
The SBU-BNL research team synthesized a two-dimensional structure and successfully trapped argon atoms inside the nanosized pore structure at room temperature. This achievement will enable scientists to use traditional surface-science tools — such as x-ray photoelectron and infrared reflection absorption spectroscopy — to perform detailed studies of single gas atoms in confinement. The knowledge gained from such research could inform the design, selection and improvement of adsorbent materials and membranes for capturing gases such as radioactive krypton and xenon generated by nuclear power plants.
Mengen Wang, a PhD candidate from Stony Brook’s Department of Materials Science and Chemical Engineering, carried out calculations under the supervision of Deyu Lu, a physicist at Brookhaven Lab’s Center for Functional Nanomaterials (CFN). Theoretical computation helped to link all the experimental evidence together to form a coherent understanding of this fascinating system.
Theory and computation provided an atomic model of the argon nanocage, in particular the preferred location of the trapped Ar atom. Theory plays the key role of a “microscope” that can tell where the Ar atom wants to go based on quantum mechanical laws. Theory and computation provide insights on the mechanism of the adsorption/desorption (how the Ar atom comes in and leaves the nanocage). The calculated adsorption and desorption barriers can be used to obtain the adsorption/desorption rates that are necessary to describe such processes.
Nusnin Akter, also a Materials Science and Chemical Engineering PhD candidate, performed infrared reflection absorption spectroscopy (IRRAS) experiments under the guidance of CFN staff scientist Jorge Anibal Boscoboinik and SBU Assistant Professor Taejin Kim. The IRRAS technique showed how the atoms were connected, allowing the team to look at the vibrations between atoms and see what bonds were breaking and forming.
This research is supported by the U.S. Department of Energy, Office of Basic Energy Sciences.