Theoretical Study of Oxygen Vacancy on Indium Oxide for Promoted Photothermal Catalytic Water Splitting

Solar-induced photothermal catalytic H2O splitting is a promising method for H2 production. On metal oxides, the interaction between H2O and the surface can lead to the formation of oxygen vacancies (VOs) and alter the reaction pathway for overall H2O splitting. Herein, the free energy profiles of two different pathways on the In2O3 (110) surface are calculated based on density functional theory, and the relation between surface VO formation and the reactivity of surface VOs reveals that surface VOs with a lower formation energy are more unfavorable for H2 evolution. Doping In2O3 with a transition metal can effectively enhance the electron transfer from the surface O atoms to the doped metal, benefitting the formation of surface VOs and causing the doped metal to become the active reaction center for H2O splitting.