Vacancy‐Rich Monolayer BiO2−x as a Highly Efficient UV, Visible, and Near‐Infrared Responsive Photocatalyst

Abstract Vacancy‐rich layered materials with good electron‐transfer property are of great interest. Herein, a full‐spectrum responsive vacancy‐rich monolayer BiO 2− x has been synthesized. The increased density of states at the conduction band (CB) minimum in the monolayer BiO 2− x is responsible for the enhanced photon response and photo‐absorption, which were confirmed by UV/Vis‐NIR diffuse reflectance spectra (DRS) and photocurrent measurements. Compared to bulk BiO 2− x , monolayer BiO 2− x has exhibited enhanced photocatalytic performance for rhodamine B and phenol removal under UV, visible, and near‐infrared light (NIR) irradiation, which can be attributed to the vacancy V Bi‐O ′′′ as confirmed by the positron annihilation spectra. The presence of V Bi‐O ′′′ defects in monolayer BiO 2− x promoted the separation of electrons and holes. This finding provides an atomic level understanding for developing highly efficient UV, visible, and NIR light responsive photocatalysts.