Predicting the Band Structure of Mixed Transition Metal Oxides: Theory and Experiment

Abstract

Fuel production from sunlight using mixed metal oxide photocatalysts is a promising route for harvesting solar energy. While photocatalytic processes can operate with high efficiency using UV light, it remains a challenge of paramount importance to drive them with visible light. Engineering the electronic energy band structure of mixed metal oxides through judicious control of atomic composition is a promising route to increasing visible light photoresponse. The goal of this paper is to develop a simple mixed metal oxide band structure (MMOBS) method to predict the electronic band structure of mixed metal oxides. Several materials in the Ti−Fe−O system that span the composition spectrum were considered in this study: anatase TiO2, Fe-doped anatase TiO2, ilmenite TiFeO3, Ti-doped hematite α-Fe2O3, and hematite α-Fe2O3. The predictions by the MMOBS method for the Ti−Fe−O system were tested and confirmed using first-principles density functional theory (DFT) calculations and experimental UV−visible absorptio...