- Collection:
- Atlanta University and Clark Atlanta University Theses and Dissertations
- Title:
- DFT Study on the Relative Stabilities and Electronic Properties of Various Structures of Double Nitrogen Doped Graphene
- Creator:
- Alzaaqi, Nada
- Date of Original:
- 2024-05
- Subject:
- Degrees, Academic
Dissertations, Academic - Location:
- United States, Georgia, Fulton County, Atlanta, 33.749, -84.38798
- Medium:
- born digital
- Type:
- Text
- Format:
- application/pdf
- Description:
- Graphene-based materials have been widely researched for their fascinating features. It is known that pristine graphene has zero bandgap, and it is crucial to tune its electronic properties for enhancing a variety of prospective applications. Modification of graphene with heteroatom substitution is one of the emerging approaches to fine-tune its electronic and chemical properties. Nitrogen doped graphene was predicted and experimentally realized in manipulating the properties of graphene for potential applications in diverse research areas. In this study, we considered a finite-sized graphene model, C186H36, to investigate the double nitrogen doping in graphene layer. The position and direction dependence of double nitrogen doping in graphene sheet were examined to understand the stability of the system as well as the electronic properties. Density functional theory (DFT) calculations were performed to explore the double nitrogen substitution in a finite-sized graphene consisting of 186 carbon atoms, and the edges were terminated with hydrogen atoms. All structures were fully optimized using density functional theory (DFT) at B3LYP/6-31G(d) level. HOMO-LUMO energy gap values for all the isomers of two nitrogen doped graphene were calculated using TPSSh/6-31G(d)//B3LYP/6-31G(d) level. First, we investigated the double nitrogen doping within six-membered rings of the graphene. We found that the location of the ring plays a key role in determining the stabilities of double nitrogen dopants. Our computational study shows that highly preferred structures have two nitrogen atoms positioned at the zigzag edge. Second, we examined the preference of having two nitrogen doping located along two directions of graphene. The results revealed the preferential direction in which the nitrogen atoms prefer to locate. Importantly, the bandgap can be opened by controlling the sites of nitrogen doping into the graphene network. The selectivity of the direction plays a role in band gap opening. This comprehensive computational study concludes that doping of two nitrogen atoms in particular sites will be an effective approach to open the band gap, which is essential for many chemical, biological and electronic applications.
- External Identifiers:
- Metadata URL:
- http://hdl.handle.net/20.500.12322/cau.td:2024_alzaaqi_nada
- Rights Holder:
- Clark Atlanta University
- Holding Institution:
- Atlanta University Center Robert W. Woodruff Library
- Rights:
-
