Lattice distortion and electron charge redistribution induced by defects in graphene

Interactions between defects in graphene and the lattice distortion and electronic charge localization induced by the defect interactions are studied by tight-binding (TB) calculations using the recently developed three-center TB potential model. The interaction between two 5-7 Stone-Wales defects gliding along the zig-zag direction of the graphene, which has been observed by experiment, is studied at first to validate the TB calculations. Reconstructed divacancy defect pairs and di-adatom defect pairs separated along the glide zigzag (ZZ) and armchair (AC) directions in graphene respectively are then studied. We show that the characteristic (i.e., attractive or repulsive) and the strength of interactions between these defects are dependent on the type of defects and on the direction and distance of the defect separation on graphene.While elastic interaction due to the graphene lattice distortion induced by the defect has significant contribution to the total interaction energy, redistribution of electron charges caused by the defects also plays an important role in the defect-defect interaction.

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“…respectively from our previous calculations. 36 Although there is some noises in the calculation results, from Fig. 5…”

Section: Resultsmentioning

confidence: 99%

Defect Interaction and Deformation in Graphene

et al. 2020

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“…Note that the Mn 2p 3/2 binding energy of 5CuBir was shifted from 642.4 to 641.9 eV in comparison with raw birnessite, illustrating that the content of Mn 3+ or Mn 2+ increased after copper‐doping. According to the relevant literatures,, the lattice distortion could induce an interfacial charge redistribution and promote the reduction of Mn 4+ .…”

Section: Resultsmentioning

confidence: 99%

Catalytic Process Optimization of Birnessite‐based Fenton‐like Reaction with Surface Cu²⁺ Modification

Zang

Jin

et al. 2018

ChemCatChem

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Layer-structured birnessite (d-MnO 2 ) has been applied recently in the heterogeneous Fenton-like process. However, easy deactivation and low utilization efficiency of H 2 O 2 limit its practical application. The catalytic processes of H 2 O 2 on birnessite were successfully regulated via surface chemical modification as Cu 2 + ions were intercalated into the birnessite by the ion-exchange method (CuBir). The triple-corner-sharing inner-sphere surface complexes of Cu 2 + ions (TCS species) formed above Mn vacancies could effectively weaken the over-complexation of H 2 O 2 on the surface of [MnO 6 ] sheets, and then decrease the self-consumption of surface-formed superoxide radicals. The surface TCS species have excellent Fenton-like performances and enhance the conversion efficiency of H 2 O 2 into reactive oxygen species (ROS). Moreover, the surface Cu 2 + -modification engineering could prevent deactivation owing to degradation intermediate residues and improve the recyclability of catalyst.

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“…where k is the wave number and E k is the energy corresponding to the wave number k), and cause charge carriers to be highly localized in the defective regions [48,49]. Moreover, it has been shown that both strain and isolated vacancies can reduce the linear dispersion, introduce Fermi level shifting, manifest metallic behavior by band crossing, and also introduce very narrow direct and indirect band gaps [49,50].…”

Section: Electronic Structure and Effects Of Hydrogen Passivationmentioning

confidence: 99%

Electronic structure of electron-irradiated graphene and effects of hydrogen passivation

Weerasinghe

Ramasubramaniam

Maroudas

2018

Mater. Res. Express

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We report results for the electronic structure of irradiated and irradiation-induced amorphized graphene based on first-principles density functional theory calculations, using models of irradiated graphene sheets that were initially relaxed structurally according to molecular-dynamics simulations. We find that localized states appear at the Fermi level upon irradiation damage and the corresponding local density of states increases with increasing defect density. Electronic structure calculations show that band flattening occurs due to electron localization in the vicinity of irradiation-induced defects and reduces the charge carrier mobility. This band flattening effect becomes stronger with increasing defect density due to a greater degree of carrier localization at irradiation-induced carbon dangling bonds. Passivating these dangling bonds with hydrogen atoms delocalizes the charge density, reduces the density of states at the Fermi level, and increases the band dispersion. Hydrogen passivation also has the additional effect of quenching any localized magnetic moments at dangling bonds. Our studies show that defect engineering of graphene-even at a gross level without atomic-scale precision-can be employed to tune its properties for additional electronic functionality.

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Lattice distortion and electron charge redistribution induced by defects in graphene

Cited by 31 publications

References 30 publications

Defect Interaction and Deformation in Graphene

Defect Interaction and Deformation in Graphene

Catalytic Process Optimization of Birnessite‐based Fenton‐like Reaction with Surface Cu²⁺ Modification

Electronic structure of electron-irradiated graphene and effects of hydrogen passivation

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Lattice distortion and electron charge redistribution induced by defects in graphene

Cited by 31 publications

References 30 publications

Defect Interaction and Deformation in Graphene

Defect Interaction and Deformation in Graphene

Catalytic Process Optimization of Birnessite‐based Fenton‐like Reaction with Surface Cu2+ Modification

Electronic structure of electron-irradiated graphene and effects of hydrogen passivation

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Product

Resources

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Catalytic Process Optimization of Birnessite‐based Fenton‐like Reaction with Surface Cu²⁺ Modification