Title: Proton transport through one-atom-thick crystals

Reporter：Sheng Hu           The University of Manchester             

Time: 10：00-11：30  29th December 2016

Adress : Chemistry building 234 meetingroom，Xiamen University

Abstract：
Graphene is increasingly explored as a possible platform for developing novel separation technologies ^[1,2]. However, a perfect graphene monolayer is impermeable to all atoms and molecules under ambient conditions ^{[3, 4]}– only accelerated atoms possess the kinetic energy required to do this ^[5]. In this talk I will present proton transport through one-atom-thick membranes, including graphene, hexagonal boron nitride (h-BN) and molybdenum disulphide (MoS₂). I will first describe a Nafion based proton injection ^[6] experimental setup in which proton transport signals are detected from transport and mass spectroscopy measurements; I will then present that proton transport can be further enhanced by decorating the graphene and h-BN membranes with catalytic metal nanoparticles. The results demonstrate that monolayers of graphene and h-BN are highly permeable to thermal protons under ambient conditions, while no proton transport is detected for thicker crystals such as monolayer MoS₂, bilayer graphene or multilayer h-BN ^[7]. At last, I’ll introduce a hydrogen isotope separation technique. Our result shows a hydrogen/deuterium separation ratio as high as 10, which is significantly higher than classical separation methods (usually with ratio about 1.5).
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2. S. Garaj et al. Graphene as a subnanometre trans-electrode membrane. Nature 467, 190–1933 (2010).
3. J. S. Bunch et al. Impermeable atomic membranes from graphene sheets. Nano Lett. 8, 2458–2462 (2008).
4. V. Berry. Impermeability of graphene and its applications. Carbon 62, 1–10 (2013).
5. E. Stolyarova et al. Observation of graphene bubbles and effective mass transport under graphene films. Nano Lett. 9, 332–337 (2009).
6. H. Morgan, R. Pethig, G. T. Stevens. A proton-injecting technique for the measurement of hydration-dependent protonic conductivity. J. Phys. E 19, 80–82 (1986).
7. S. Hu et al. Proton transport through one-atom-thick crystals. Nature 516, 227–230 (2014).
8. M. Lozada-Hidalgo, S. Hu et al., Sieving hydrogen isotopt through two-dimensional crystals. Science, 351, 68(2016).

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