Titanium oxide (TiO2), a metal oxide known for its versatility and photocatalytic activity, has shown potential as a useful catalyst support in industrial processes. Catalyst synthesis can generate oxygen vacancies, which impacts the phase stability and electronic structure of TiO2 supports. Oxygen vacancy can also change titanium atoms from their normal Ti4+ state to Ti3+, which creates new electronic states in the material band gaps and enhances the photoactivity of TiO2. In this project, we aim to use Density Functional Theory (DFT) calculations and data-driven insights to study energetics of oxygen vacancies on TiO2, specifically focusing on the H2 adsorption process. In particular, we use Vienna Ab initio Simulation Package (VASP) for electronic structure calculations and generate structures using Pymatgen (Python Materials Genomics) package. We begin with rutile TiO2 (001), where we aim to study the H2 adsorption process on surfaces with oxygen vacancies in different positions, comparing the adsorption configuration, adsorption energy, and electronic properties of such surfaces. By comparing the H2 adsorption energy for the most stable surfaces with O2 vacancy and without O2 vacancy, we found that O2 vacancies make H2 adsorption more thermodynamically favorable. To explain this, we plan to examine charge redistribution near the vacancy and use density of states (DOS) analysis to see how defect states near the Fermi level promote stronger H2–surface interactions.
