Effects of Edge Oxidation on the Stability and Half-Metallicity of Graphene Quantum Dots

Authors

  • Meilian Zhao,

    1. College of Chemistry, Key Laboratory of Green Chemistry and Technology in Ministry of Education, Sichuan University, Chengdu 610064 (P. R. China)
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  • Feng Yang,

    1. College of Chemistry, Key Laboratory of Green Chemistry and Technology in Ministry of Education, Sichuan University, Chengdu 610064 (P. R. China)
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  • Prof. Ying Xue,

    1. College of Chemistry, Key Laboratory of Green Chemistry and Technology in Ministry of Education, Sichuan University, Chengdu 610064 (P. R. China)
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  • Prof. Dan Xiao,

    Corresponding author
    1. College of Chemistry, Key Laboratory of Green Chemistry and Technology in Ministry of Education, Sichuan University, Chengdu 610064 (P. R. China)
    • College of Chemistry, Key Laboratory of Green Chemistry and Technology in Ministry of Education, Sichuan University, Chengdu 610064 (P. R. China)

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  • Prof. Yong Guo

    Corresponding author
    1. College of Chemistry, Key Laboratory of Green Chemistry and Technology in Ministry of Education, Sichuan University, Chengdu 610064 (P. R. China)
    • College of Chemistry, Key Laboratory of Green Chemistry and Technology in Ministry of Education, Sichuan University, Chengdu 610064 (P. R. China)

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  • A Comprehensive First-Principles Study

Abstract

A comprehensive first-principles theoretical study of the electronic properties and half-metallic nature of zigzag edge-oxidized graphene quantum dots (GQDs) is carried out by using density functional theory (DFT) with the screened exchange hybrid functional of Heyd, Scuseria and Ernzerhof (HSE06). The oxidation schemes include -OH, -COOH and -COO groups. We identify oxidized GQDs whose opposite spins are localized at the two zigzag edges in an antiferromagnetic-type configuration, showing a spin-polarized ground state. Oxidized GQDs are more stable than the corresponding fully hydrogenated GQDs. The partially hydroxylated and carboxylated GQDs with the same size exhibit half-metallic state under almost the same electric-field intensity whereas fully oxidized GQDs behave as spin-selective semiconductors. The electric-field intensity inducing the half metal increases with the length of the partially oxidized GQDs, ranging from M=4 to 7.

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