Electronic structure tailoring of BiOBr (0 1 0) nanosheets by cobalt doping for enhanced visible-light photocatalytic activity

Abstract

Generally, pristine semiconductor materials are difficult to own excellent photocatalytic performance, and doping is considered an effective strategy to improve their performance. Herein, Co-doped BiOBr (0 1 0) was successfully synthesized. The improved performance could be attributed to the enhanced charge separation efficiency and the expanded light absorption region. Moreover, Co-doped BiOBr (0 1 0) owned relatively rough crystal surface with rich atomic defects and large specific surface area, which leaded to its excellent adsorption performance that contributed to the hole-dominated degradation process. Through density functional theoretical (DFT) calculation, the effect of Co doping on electronic structure of BiOBr was investigated, indicating that an additional energy level inserted into the band gap of Co-doped BiOBr, the band structure of Co-doped BiOBr was more intensive than that of BiOBr, and the CBM and VBM of the Co-doped BiOBr shifted towards lower energy regions. Tetracycline hydrochloride was chosen to further evaluate the photocatalytic performance of as-prepared Co-doped BiOBr (0 1 0), and 83% of tetracycline hydrochloride was degrade within 30 min. Finally, the visible-light driven catalytic mechanism of Co-doped BiOBr (0 1 0) was elucidated. Thus, a feasible strategy was proposed for the fabrication of excellent visible-light-driven photocatalytic materials.