Density Functional Investigation of Graphene Doped with Amine‐Based Organic Molecules

Abstract

To improve the electronic properties of graphene, many doping techniques have been studied. Herein, we investigate the electronic and molecular structure of doped graphene using density functional theory, and we report the effects of amine-based benzene dopants adsorbed on graphene. Density functional theory (DFT) calculations were performed to determine the role of amine-based aromatic compounds in graphene doping. These organic molecules bind to graphene through long-range interactions such asπ-πinteractions and C-H⋯πhydrogen bonding. We compared the electronic structures of pristine graphene and doped graphene to understand the electronic structure of doped graphene at the molecular level. Also, work functions of doped graphene were obtained from electrostatic potential calculations. A decrease in the work function was observed when the amine-based organic compounds were adsorbed onto graphene. Because these systems are based on physisorption, there was no obvious band structure change at pointKat the Fermi level after doping. However, the amine-based organic dopants did change the absolute Fermi energy levels. In this study, we showed that the Fermi levels of the doped graphene were affected by the HOMO energy level of the dopants and by the intermolecular charge transfer between the adsorbed molecules and graphene.

One-Dimensional Multichannel g-C3N4.7 Nanostructure Realizing an Efficient Photocatalytic Hydrogen Evolution Reaction and Its Theoretical Investigations

“…These amine groups also act as a shallow electron donor whose free electron lone pairs also effectively and additionally contributed to the reduction of H + to H 2 as seen under the Computational Procedure section. 19,52 Here, more electron density is transferred to the CB of MDY from the −NH x groups as the Fermi level of the amine group is believed to lie above (more negative than) the CB of g-C 3 N 4.7 based on our current band structure experiment and reported electronic structure of liquid ammonia 53 and amine-doped graphene, 54,55 and as shown in Figure 4e (from DFT). Similar characteristics are seen in the electronic band structure of the NH 3 molecule adsorbed (ex situ doping) on a Si nanowire host material, which yields ntype doping, where the Fermi level of NH 3 found pinned near the CB of the host material.…”

Charge transfer of carbon nanomaterials for efficient metal‐free electrocatalysis

“…[84] It was also revealed by the DFT calculation that amine-based organic molecules promote an n-type doping influence on graphene owing to the decrease in the work function of graphene due to the formation of a graphene-organic complex. [85] However, the adsorption of amine-based molecules onto graphene do not alter its mobility. So far, various polymers (e.g., n-methyl-2-pyrrolidone, hexamethyldisilazane), [86] copolymer (epichlorohydrin-dimethylamine copolymer), [87] and organic and inorganic molecules (e.g., O 2 , NO, NO 2 , H 2 O, CO, CH 4 , CH 3 OH, C 6 H 5 NO 2 ) [51,[88][89][90][91][92][93] have been adsorbed onto carbon nanomaterials, which, along with carbon-carbon hybrids (e.g., CNT-C 60 ) and carbon-phosphorus hybrid materials, have been used for various potential electrocatalytic applications.…”