First principles study of oxygen adsorption on nickel-doped graphite

Nahali, M ; Sharif University of Technology | 2012

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  1. Type of Document: Article
  2. DOI: 10.1080/00268976.2012.656719
  3. Publisher: 2012
  4. Abstract:
  5. Density functional theory is used in a spin-polarized plane wave pseudopotential implementation to investigate molecular oxygen adsorption and dissociation on graphite and nickel-doped graphite surfaces. Molecular oxygen physisorbs on graphite surface retaining its magnetic property. The calculated adsorption energy is consistent with the experimental value of 0.1eV. It is found that substituting a carbon atom of the graphite surface by a single doping nickel atom (2.8% content) makes the surface active for oxygen chemisorption. It is found that the molecular oxygen never adsorbs on doping nickel atom while it adsorbs and dissociates spontaneously into atomic oxygens on the carbon atoms which are bound to the nickel. The adsorption energy of 1.4eV and zero activation energy barrier indicate that O 2 dissociative adsorption is both thermodynamically and kinetically favoured over the surface. The large electric field near the doping nickel atom along with the excess electrons on the neighbouring carbon atoms, which are bound to the nickel induce molecular oxygen to adsorb and dissociate favourably
  6. Keywords:
  7. A-carbon ; Adsorption energies ; Atomic oxygen ; Carbon atoms ; Dissociative adsorption ; Excess electrons ; Experimental values ; First-principles study ; Graphite surfaces ; Molecular oxygen adsorption ; Nickel atoms ; Oxygen adsorption ; Oxygen chemisorption ; Plane wave ; Pseudopotentials ; Spin-polarized ; Surface active ; Zero activation energy ; Atoms ; Chemisorption ; Density functional theory ; Electric fields ; Gas adsorption ; Graphite ; Magnetic properties ; Molecular oxygen ; Oxygen ; Photodissociation ; Nickel
  8. Source: Molecular Physics ; Volume 110, Issue 13 , Feb , 2012 , Pages 1437-1445 ; 00268976 (ISSN)
  9. URL: http://www.tandfonline.com/doi/abs/10.1080/00268976.2012.656719