Orientational Alignment of Oxygen Vacancies: Electric-Field-Inducing Conductive Channels in TiO₂ Film to Boost Photocatalytic Conversion of CO₂ into CO

Abstract

Oxide semiconductors are widely used in the photocatalytic fields, and introducing oxygen vacancies is an effective strategy to improve their photocatalytic efficiency. However, oxygen vacancies in the bulk often act as the recombination centers of electron-hole pairs, which accelerates the recombination of electron-hole pairs. In this paper, we propose a strategy of electric field treatment and apply it to a TiO₂ film with oxygen vacancies to promote the photocatalytic efficiency. After treatment by an electric field, the conductive channels consisting of oxygen vacancies are formed in the TiO₂ film, which greatly decreases the resistance by almost 6 × 10³ times. The yield of CO can reach up to 1.729 mmol g_cat^-1 h^-1, which is one of the best performances among the reported TiO₂-based catalysts. This work provides an effective and feasible way for enhancing photocatalytic activity through an electric field, and this method is promising for wide use in the field of catalysis.