26–29 Oct 2026
Africa/Johannesburg timezone

Electronic, and HER properties of graphene oxide and quaternary nitrogen doped graphene oxide: A DFT approach

27 Oct 2026, 15:10
20m
Oral Presentation Session 4

Speaker

SAMWEL OPIYO (UNIVERSITY OF SOUTH AFRICA(UNISA))

Description

The development of economical and efficient nanomaterial for enhancement of hydrogen production requires tuning of surface and electronic properties to facilitate optimal attachment of hydrogen ion, transfer of electrons and desorption of H2 gas. This tuning process may be experimentally uneconomical in terms of cost and time. Computational approach ensures proper utilization of these resources by first optimizing through configuration testing before embarking on laboratory synthesis and application. In this work, a 3x3x1 graphene oxide(GO) structure with C/O ratio of 2.25 and quaternary nitrogen doped graphene oxide (NGO) were modeled using visualization for electronic and structural analysis (VESTA) software. Density functional theory (DFT) calculations was carried out using Vienna Ab initio Simulation Package (VASP). To investigate the electronic and HER characteristics of the material at variable nitrogen and H configurations, projected augmented wave (PAW) method and the Perdew-Burker-Ernzerhof (PBE) exchange correlation functional was used with force and energy convergence criteria set at 0.02 eVÅ^(-1) and 10-6 eV respectively. The results indicted significant reduction of electronic bandgap of GO upon introduction of nitrogen from 1.33 eV for GO to 0.78 eV for NGO with two nitrogen atoms, demonstrating improvement of electrical conductivity of the material. The calculated Gibbs free energy(∆G_H) for HER at varied H positions and N configurations demonstrated significant variations with the most favorable position exhibiting ∆G_H =0.0088 eV, closer to the thermodynamic ideal value for platinum based catalysts. These findings demonstrate the significant effect of N incorporation in improving the electronic and HER activities of metal free GO.

Author

SAMWEL OPIYO (UNIVERSITY OF SOUTH AFRICA(UNISA))

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