Advances in Manufacturing ›› 2017, Vol. 5 ›› Issue (3): 289-298.doi: 10.1007/s40436-017-0180-y

• Articles • Previous Articles    

Hydrogenation of graphene nanoflakes and C-H bond dissociation of hydrogenated graphene nanoflakes:a density functional theory study

Sheng Tao1, Hui-Ting Liu1, Liu-Ming Yan1, Bao-Hua Yue1, Ai-Jun Li2   

  1. 1 Department of Chemistry, College of Sciences, Shanghai University, Shanghai 200444, P. R. China;
    2 Research Center for Composite Materials, Shanghai University, Shanghai 200444, P. R. China
  • Received:2017-01-21 Revised:2017-04-26 Online:2017-09-25 Published:2017-09-25
  • Contact: Liu-Ming Yan,E-mail:liuming.yan@t.shu.edu.cn E-mail:liuming.yan@t.shu.edu.cn
  • Supported by:

    This work is supported by NSAF (Grant No. U1630102) and the National Natural Science Foundation of China (Grant Nos. 21573143 and 21376147). The authors also acknowledge the High-Performance Computing Center and the Laboratory for Microstructures, Shanghai University for computing and structural characterization.

Abstract:

The Gibbs free energy change for the hydrogenation of graphene nanoflakes Cn (n=24, 28, 30 and 32) and the C-H bond dissociation energy of hydrogenated graphene nanoflakes CnHm (n=24, 28, 30 and 32; and m=1, 2 and 3) are evaluated using density functional theory calculations. It is concluded that the graphene nanoflakes and hydrogenated graphene nanoflakes accept the ortharyne structure with peripheral carbon atoms bonded via the most triple bonds and leaving the least unpaired dangling electrons. Five-membered rings are formed at the deep bay sites attributing to the stabilization effect from the pairing of dangling electrons. The hydrogenation reactions which eliminate one unpaired dangling electron and thus decrease the overall multiplicity of the graphene nanoflakes or hydrogenated graphene nanoflakes are spontaneous with negative or near zero Gibbs free energy change. And the resulting C-H bonds are stable with bond dissociation energy in the same range as those of aromatic compounds. The other C-H bonds are not as stable attributing to the excessive unpaired dangling electrons being filled into the C-H anti-bond orbital.

The full text can be downloaded at https://link.springer.com/article/10.1007/s40436-017-0180-y

Key words: Graphene nanoflake, Hydrogenated graphene nanoflake, Orth-aryne, Hydrogenation reaction, Bond dissociation energy, Density functional theory