Xenon trapping in diverse metal-supported silica nanocages

Separating and purifying noble gases is challenging due to their chemical inertness, resulting in processes that are both energy-intensive and expensive. An alternative approach involves trapping noble gases within metal-supported nanocages through physical confinement and electronic interactions—a technique successfully demonstrated at low pressures at room temperature. In this study, we investigate how different metal supports affect the trapping efficiency of xenon in silicate nanocages. We employed a Langmuir–Blodgett trough to deposit near one layer of nanocages onto single crystals of Ag(111), Au(111), and Ru(0001). Subsequently, we calcined and reduced the samples to activate their xenon-trapping capabilities. Following this, X-ray photoelectron spectroscopy (XPS) was used to quantify the trapped xenon across different stereochemical environments. As a result, all metal substrates demonstrated xenon trapping capabilities to varying degrees, with the gold substrate capturing the highest fraction per nanocage after initial exposure to xenon plasma. These findings suggest that metal substrates can be tailored to optimize noble gas trapping, offering an energy-efficient and cost-effective alternative to conventional industrial separation methods.