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Title: Nitrogen-Doping Enables Covalent-Like pi-pi Bonding between Graphenes

Abstract

The neighboring layers in bi-layer (and few-layer) graphenes of both AA and AB stacking motifs are known to be separated at a distance corresponding to van der Waals (vdW) interactions. In this Letter, we present for the first time a new aspect of graphene chemistry in terms of a special chemical bonding between the giant graphene molecules . Through rigorous theoretical calculations, we demonstrate that the N-doped graphenes (NGPs) with various doping levels can form an unusual two-dimensional (2D) pi pi bonding in bi-layer NGPs bringing the neighboring NGPs to significantly reduced interlayer separations. The interlayer binding energies can be enhanced by up to 50% compared to the pristine graphene bi-layers that are characterized by only vdW interactions. Such an unusual chemical bonding arises from the pi pi overlap across the vdW gap while the individual layers maintain their in-plane pi-conjugation and are accordingly planar. The existence of the resulting interlayer covalent-like bonding is corroborated by electronic structure calculations and crystal orbital overlap population (COOP) analyses. In NGP-based graphite with the optimal doping level, the NGP layers are uniformly stacked and the 3D bulk exhibits metallic characteristics both in the in-plane and along the stacking directions.

Authors:
 [1];  [2];  [2];  [1]
  1. Georgetown University
  2. ORNL
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Center for Nanophase Materials Sciences (CNMS)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1193191
DOE Contract Number:  
DE-AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Nano Letters; Journal Volume: TBD
Country of Publication:
United States
Language:
English

Citation Formats

Tian, Yong-Hui, Huang, Jingsong, Sumpter, Bobby G, and Kertesz, Prof. Miklos. Nitrogen-Doping Enables Covalent-Like pi-pi Bonding between Graphenes. United States: N. p., 2015. Web.
Tian, Yong-Hui, Huang, Jingsong, Sumpter, Bobby G, & Kertesz, Prof. Miklos. Nitrogen-Doping Enables Covalent-Like pi-pi Bonding between Graphenes. United States.
Tian, Yong-Hui, Huang, Jingsong, Sumpter, Bobby G, and Kertesz, Prof. Miklos. Thu . "Nitrogen-Doping Enables Covalent-Like pi-pi Bonding between Graphenes". United States. doi:.
@article{osti_1193191,
title = {Nitrogen-Doping Enables Covalent-Like pi-pi Bonding between Graphenes},
author = {Tian, Yong-Hui and Huang, Jingsong and Sumpter, Bobby G and Kertesz, Prof. Miklos},
abstractNote = {The neighboring layers in bi-layer (and few-layer) graphenes of both AA and AB stacking motifs are known to be separated at a distance corresponding to van der Waals (vdW) interactions. In this Letter, we present for the first time a new aspect of graphene chemistry in terms of a special chemical bonding between the giant graphene molecules . Through rigorous theoretical calculations, we demonstrate that the N-doped graphenes (NGPs) with various doping levels can form an unusual two-dimensional (2D) pi pi bonding in bi-layer NGPs bringing the neighboring NGPs to significantly reduced interlayer separations. The interlayer binding energies can be enhanced by up to 50% compared to the pristine graphene bi-layers that are characterized by only vdW interactions. Such an unusual chemical bonding arises from the pi pi overlap across the vdW gap while the individual layers maintain their in-plane pi-conjugation and are accordingly planar. The existence of the resulting interlayer covalent-like bonding is corroborated by electronic structure calculations and crystal orbital overlap population (COOP) analyses. In NGP-based graphite with the optimal doping level, the NGP layers are uniformly stacked and the 3D bulk exhibits metallic characteristics both in the in-plane and along the stacking directions.},
doi = {},
journal = {Nano Letters},
number = ,
volume = TBD,
place = {United States},
year = {Thu Jan 01 00:00:00 EST 2015},
month = {Thu Jan 01 00:00:00 EST 2015}
}