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Condensed Matter Physics Seminar

  • Address
    Marshak Science
    City College of New York
    160 Convent Ave., New York, NY  10031

    Location
    Marshak Science, 418N

    p: 212.650.5516

    Admission
    Free

  • Event Details

    "The influence of graphene curvature on hydrogen adsorption: towards hydrogen storage devices."

    The influence of graphene curvature on hydrogen adsorption:
    towards hydrogen storage devices
    Sarah Goler
    Laboratorio NEST, Istituto Nanoscienze – CNR and Scuola Normale Superiore,
    Center for Nanotechnology Innovation @ NEST, Istituto Italiano di Tecnologia,
    Piazza San Silvestro 12, 56127 Pisa, Italy
    Graphene is an intriguing material that shows promises for hydrogen storage. It is a single layer of carbon atoms arranged in a honeycomb lattice. I will introduce the current state of the art hydrogen storage materials followed by the possibility of using graphene as a scaffold for hydrogen. Theory predicts that the energy barrier for adsorbing and desorbing atomic hydrogen attached to the pi-bonds of graphene can be removed making it possible to attach and release hydrogen at room temperature, a mechanism that can be exploited for hydrogen storage applications [1]. I will show experimental evidence that the energy barrier for adsorbing atomic hydrogen attached to the pi-bonds depends on the curvature of graphene.
    To test these predictions, scanning tunneling microscopy experiments were performed on epitaxial graphene grown on SiC(0001) which has a periodic intrinsic curvature [2]. The positions and stable conformations of the hydrogen atoms on the atomically resolved lattice were studied as a function of curvature by hydrogenating the sample in situ [3]. It was found that atomic hydrogen binds to the carbon atoms in the convexly curved areas, as expected from DFT calculations [1]. The desorption energy barrier of hydrogen on the maximally convex area of graphene was calculated [3]. The curvature dependent graphene-hydrogen interaction results presented are an encouraging step towards a hydrogen storage device that adsorbs and releases hydrogen independent of temperature and pressure changes.
    [1] V. Tozzini and V. Pellegrini. J. Phys. Chem. C 115, 25523 (2011).
    [2] F. Varchon et al. Phys. Rev. B 77, 235412(2008).
    [3] S. Goler et al. submitted for review.
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