Anionic Group Self-Doping as a Promising Strategy: Band-Gap Engineering and Multi-Functional Applications of High-Performance CO32–-Doped Bi2O2CO3

Abstract

We herein demonstrate self-doping of the CO 3 2– anionic group into a wide bandgap semiconductor Bi 2 O 2 CO 3 realized by a one-pot hydrothermal technique. The photoresponsive range of the self-doped Bi 2 O 2 CO 3 can be extended from UV to visible light and the band gap can be continuously tuned. Density functional theory (DFT) calculation results demonstrate that the foreign CO 3 2– ions are doped in the caves constructed by the four adjacent CO 3 2– ions and the CO 3 2– self-doping can effectively narrow the band gap of Bi 2 O 2 CO 3 by lowering the conduction band position and meanwhile generating impurity level. The photocatalytic performance is evaluated by monitoring NO removal from the gas phase, photodegradation of a colorless contaminant (bisphenol A, BPA) in an aqueous solution, and photocurrent generation. In comparison with the pristine Bi 2 O 2 CO 3 which is not sensitive to visible light, the self-doped Bi 2 O 2 CO 3 exhibits drastically enhanced visible-light photoreactivity, which is also superior to that of many other well-known photocatalysts such as P25, C 3 N 4, and BiOBr. The highly enhanced photocatalytic performance is attributed to combination of both efficient visible light absorption and separation of photogenerated electron–hole pairs. The self-doped Bi 2 O 2 CO 3 also shows decent photochemical stability, which is of especial importance for its practical applications. This work demonstrates that self-doping with an anionic group enables the band gap engineering and the design of high-performance photocatalysts sensitive to visible light.