Atomistic Materials Modeling Applied to 2D Heterostructures and Electrocatalysis
Open Access
Author:
Holoviak, Stephen
Graduate Program:
Materials Science and Engineering
Degree:
Doctor of Philosophy
Document Type:
Dissertation
Date of Defense:
May 24, 2024
Committee Members:
John Mauro, Program Head/Chair Kristen Fichthorn, Outside Unit & Field Member Susan Sinnott, Chair & Dissertation Advisor Joshua Robinson, Major Field Member Ismaila Dabo, Major Field Member
Keywords:
Density functional theory molecular dynamics platinum gallium oxide
Abstract:
Computational modeling of materials enables property prediction for novel material systems as well as a way to enhance the understanding of experimental results. This work uses density functional theory to study a novel SiC/GaO/graphene heterostructure. By collaborating closely with experimental characterization efforts, the possible structures of the gallium oxide were determined. By comparing the energetics of monolayer and bilayer oxides, the relative amounts of the structures observed could be explained.
This work also focuses on the simulation of electrocatalytic systems using the physics-based COMB interatomic potential. The reduced cost of an empirical potential along with COMB's ability to model heterogeneous systems and external voltage make it a good choice for electrochemical systems. The behavior of metal-electrode/water-electrolyte systems under an external voltage was carefully characterized. A major source of error in the fluctuating charge model was identified and a way to mitigate the error and improve simulation performance was developed. Additionally, implementation of an extension to the current fluctuating charge model was begun and proof of concept results are reported.
