{"id":11607,"date":"2017-09-27T20:53:15","date_gmt":"2017-09-28T03:53:15","guid":{"rendered":"http:\/\/cafe.foundation\/blog\/?p=11607"},"modified":"2017-09-27T20:53:15","modified_gmt":"2017-09-28T03:53:15","slug":"the-lightest-material-encapsulated-in-the-sheerest","status":"publish","type":"post","link":"http:\/\/cafe.foundation\/blog\/the-lightest-material-encapsulated-in-the-sheerest\/","title":{"rendered":"The Lightest Material Encapsulated in the Sheerest"},"content":{"rendered":"

Scientists may have come up with a process to wrap hydrogen-trapping magnesium with an atom-thick layer of graphene, setting up a scenario to store hydrogen in a weight-saving way.<\/p>\n

Hydrogen seems to be a perfect fuel, but like all perfect things, an unattainable one.\u00a0 Its lightness and smallness make it hard to contain, and pressurization required to store it adds weight to its containers.\u00a0 Flying since 2009, the Lange Antares DLR-H2<\/a> has been a test bed for hydrogen-fueled flight.\u00a0 The DLR (Germany\u2019s NASA) explains, \u201cThe developers selected a new, larger pressure vessel that, at 350 bar (5,076 pounds per square inch), now holds five kilograms of hydrogen to replace the previous tank in the external pod on the starboard wing, which provided a capacity of just two kilograms.\u201d<\/p>\n

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Lange Antares H2 in flight. Substantial pod on right wing holds only five kilograms of hydrogen – still sufficient for long-range flights<\/p><\/div>\n

It takes a substantial container and high pressure to contain hydrogen as currently used in transportation.\u00a0 Reducing or eliminating that equipment would make H2 a more viable power source for aviation.\u00a0 That is not to say some type of containment vessel would still not be necessary, but it could be substantially lighter than current systems.<\/p>\n

Researchers at the Molecular Foundry and the Advanced Light Source, Lawrence Berkeley National Laboratory; the Department of Chemical and Biomolecular Engineering,\u00a0Korea Advanced Institute of Science and Technology (KAIST), and the Department of Physics,\u00a0National Tsing Hua University, Taiwan, managed to enclose hydrogen in magnesium nanoparticle \u201cencapsulated in reduced graphene oxide.\u201d<\/a><\/p>\n

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A powdery mixture of graphene-wrapped magnesium nanocrystals, produced at Berkeley Lab, is stable in air. The mixture\u2019s energy properties show promise for use in hydrogen fuel cells. (Eun Seon Cho\/Berkeley Lab)<\/p><\/div>\n

Berkeley reports, \u201cThe study, led by Berkeley Lab researchers, drew upon a range of Lab expertise and capabilities to synthesize and coat the magnesium crystals, which measure only 3-4 nanometers (billionths of a meter) across; study their nanoscale chemical composition with X-rays; and develop computer simulations and supporting theories to better understand how the crystals and their carbon coating function together.\u201d<\/p>\n

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Thin sheets of graphene oxide (red sheets) have natural, atomic-scale defects that allow hydrogen gas molecules to pass through while blocking larger molecules such as oxygen (O2) and water (H2O). Berkeley Lab researchers encapsulated nanoscale magnesium crystals (yellow) with graphene oxide sheets to produce a new formula for metal hydride fuel cells. (Jeong Yun Kim)<\/p><\/div>\n

Normal reactivity of hydrogen and magnesium causes them to react to the oxygen, water vapor and carbon dioxide in their environment.\u00a0 Wrapping the magnesium\/hydrogen combination in graphene to form an atomically thin layer of oxidation of the crystals during their preparation.\u00a0 But surprisingly, this oxide layer doesn\u2019t seem to degrade the material\u2019s performance.<\/p>\n

Another unexpected finding, that the wrapped nanocrystals can \u201ctake up\u201d hydrogen quickly, is an important factor in refueling.\u00a0 Researchers also found that the core material can absorb \u201chydrogen gas at a much higher density than possible in a compressed hydrogen gas fuel tank at the same pressures.\u201d<\/p>\n

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A new study explains how an ultrathin oxide layer (oxygen atoms shown in red) coating graphene-wrapped magnesium nanoparticles (gold) still allows in hydrogen atoms (blue) for hydrogen storage applications. Credit: Berkeley Lab<\/p><\/div>\n

The team\u2019s paper, \u201cAtomically Thin Interfacial Suboxide Key to Hydrogen Storage Performance Enhancements of Magnesium Nanoparticles Encapsulated in Reduced Graphene Oxide,\u201d appears in the August 1 journal Nano Letters<\/em>.<\/p>\n