International Journal of Physics | Vol. 9, No. 3, March 2018 | pp. 17–24
DOI: 10.46882/2018/IJP/000095
Research Article
Title: Density Functional Theory Analysis of Catalytic Oxygen Evolution on Nitrogen-Doped Graphene Nanoribbons
Names of Authors: A. L. Silva¹, H. L. Mueller²
Authors’ Affiliations: ¹Institute of Physics, Federal University of Rio Grande do Sul, Porto Alegre, Brazil; ²Institut für Kernphysik, Karlsruher Institut für Technologie, Karlsruhe, Germany
Abstract: The electrochemical oxygen evolution reaction (OER) is essential for chemical solar energy conversion and modern water-splitting technologies. This investigation uses density functional theory calculations to analyze the catalytic performance and reaction mechanisms of oxygen evolution on nitrogen-doped graphene nanoribbons. We modeled three distinct configurations: edge pyridinic, center pyrrolic, and quaternary nitrogen doping patterns. Free energy profiles for intermediate steps leading to molecular oxygen (*OH, *O, and *OOH) were computed using the computational hydrogen electrode model. The calculations demonstrate that edge pyridinic nitrogen sites lower the activation barrier for the rate-determining step (*O -> *OOH) to 0.48 eV. This value is significantly lower than the 1.25 eV barrier calculated for pristine carbon surfaces. The overpotential required to trigger selective oxygen evolution on pyridinic configurations was estimated at -0.42 V versus the standard hydrogen electrode. Charge density difference mappings show that nitrogen doping induces localized spin polarization and electron deficiency on adjacent carbon atoms. This electronic reconfiguration stabilizes the adsorbed intermediates. These quantum mechanical insights provide theoretical guidelines for developing metal-free, carbon-based catalysts for efficient solar fuel production plants.
Keywords: Oxygen evolution reaction; density functional theory; nitrogen-doped graphene; electrocatalysis; reaction mechanism; overpotential
Manuscript Timeline: Received: December 10, 2017; Revised: January 20, 2018; Accepted: February 08, 2018; Published: March 14, 2018
Citation: Silva, A. L., & Mueller, H. L. (2018). Density Functional Theory Analysis of Catalytic Oxygen Evolution on Nitrogen-Doped Graphene Nanoribbons. International Journal of Physics, 9(3), 17–24.
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