Graphene: a Barrier to Hydrogen Permeation
- Savannah River National Laboratory, Aiken SC (United States)
Small area freestanding monolayer graphene has been shown to be impermeable to standard gases including hydrogen and helium.1 Several recent reports have suggested that graphene can be used as a hydrogen permeation barrier on metals.2 Those studies have relied on electrochemical hydrogen permeation measurements, which do a good job reproducing bulk permeability compared to gaseous diffusion but do not always reflect the real surface effects due to the difference in driving forces. This problem is magnified when measuring the permeability of thin coatings, which are dominated by surface effects. For this reason, we performed gas driven hydrogen permeation measurements of graphene coated metal samples. The diffusion of hydrogen through a metal can be described using Fick's and Sievert's Laws. Graphene-coated copper foils were prepared using chemical vapor deposition (CVD) with a methane precursor. Photo-reduced graphene samples were prepared by first sputtering a layer (∼15 nm) of copper on top of stainless steel foils. Graphene oxide in ethanol solutions were then drop cast on the surface and photo reduced using a neon lamp. A custom-designed apparatus has been assembled for measuring the hydrogen permeability of various materials. The operating principle of the system is as follows: A sample is sealed between the fore-sample and post-sample chambers using standard vacuum gaskets. Hydrogen is introduced into the fore sample region at varying pressures while the post sample region is maintained under high vacuum. Due to the concentration gradient, hydrogen then diffuses through the material and is detected using a quadrupole mass spectrometer. This process is repeated at several temperatures. The mass spectrometer was calibrated using an orifice with known conductance in place of the sample. Data collection and reduction were automated using scripts written in LabVIEW and Octave, respectively. We saw a decrease in the hydrogen permeability of copper after adding graphene to the surface for small temperature steps. This result is also observed when considering temperature steps of 20 K. Future Work: Apply this methodology to graphene-coated 316L stainless steel. The hydrogen permeability of 316L steel should also decrease with the addition of graphene to the surface. Determine methods for graphene defect reduction.
- Research Organization:
- WM Symposia, Inc., PO Box 27646, 85285-7646 Tempe, AZ (United States)
- OSTI ID:
- 23005500
- Report Number(s):
- INIS-US-21-WM-P23; TRN: US21V1482045834
- Resource Relation:
- Conference: WM2019: 45. Annual Waste Management Conference, Phoenix, AZ (United States), 3-7 Mar 2019; Other Information: Country of input: France; 5 refs.; available online at: https://www.xcdsystem.com/wmsym/2019/index.html
- Country of Publication:
- United States
- Language:
- English
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