Significant Increase in the Dipole Moment of Graphene on Functionalization: DFT Calculations and Molecular Dynamics Simulations

Madhur Babu Singh; Pallavi Jain; Faruq Mohammad; Prashant Singh; Indra Bahadur; Oyirwoth P Abedigamba

doi:10.1021/acsomega.4c00173

Significant Increase in the Dipole Moment of Graphene on Functionalization: DFT Calculations and Molecular Dynamics Simulations

ACS Omega. 2024 Mar 26;9(14):16458-16468. doi: 10.1021/acsomega.4c00173. eCollection 2024 Apr 9.

Authors

Madhur Babu Singh^{1

2}, Pallavi Jain², Faruq Mohammad³, Prashant Singh¹, Indra Bahadur⁴, Oyirwoth P Abedigamba⁵

Affiliations

¹ Department of Chemistry, Atma Ram Sanatan Dharma College, University of Delhi, Delhi 110021, India.
² Department of Chemistry, SRM Institute of Science & Technology, NCR Campus, Ghaziabad 201204, India.
³ Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Kingdom of Saudi Arabia.
⁴ Department of Chemistry, Material Science, Innovation and Modelling (MaSIM) Research Focus Area, North-West University (Mafikeng Campus), Private Bag X2046, Mmabatho 2735, South Africa.
⁵ Department of Physics, Kyambogo University, Kyambogo, P.O Box 1 Kampala, Uganda.

Abstract

The limited solubility of graphene in water can be attributed to the existence of π-π bonds connecting its layers. Functionalized graphene or graphene oxide (GO) is frequently produced in order to overcome the shortcomings of graphene. Using density functional theory (DFT) calculation, functionalized graphene with various combinations of hydroxyl, epoxy, and carboxylic functional groups were investigated computationally. The study focused on the effects of functional group combinations on the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies, giving information about the chemical reactivity and stability of the molecules under investigation. Global chemical reactivity descriptors, including chemical hardness, softness, electronegativity, chemical potential, and electrophilicity index, were calculated to further elucidate the overall stability and reactivity of the molecules. The results demonstrated that the introduction of oxygen-containing functional groups on graphene significantly influenced its electronic properties, leading to variations in the chemical reactivity and stability. Molecular electrostatic potential (MEP) maps highlighted the susceptibility of specific regions to electrophilic and nucleophilic attacks. The flexibility and stability of functionalized graphene through root mean square fluctuation (RMSF) and root mean square deviation (RMSD) analyses indicate the stability of functionalized graphene in water. This comprehensive computational investigation provides valuable insights into the design and understanding of functionalized graphene for potential applications in drug delivery.