Rose-like I-doped Bi₂O₂CO₃ microspheres with enhanced visible light response: DFT calculation, synthesis and...

Based on the crystal structure and the DFT calculation of Bi₂O₂CO₃, I^- can partly replace the CO₃^2-in Bi₂O₂CO₃ to narrow its bandgap and to enhance its visible light absorption. With this in mind, rose-like I-doped Bi₂O₂CO₃ microspheres were prepared via a hydrothermal process. This method can also be extended to synthesize rose-like Cl- or Br-doped Bi₂O₂CO₃ microspheres. Photoelectrochemical test supports the DFT calculation result that I- doping narrows the bandgap of Bi₂O₂CO₃ by forming two intermediate levels in its forbidden band. Further study reveals that I-doped Bi₂O₂CO₃ microspheres with optimized composition exhibit the best photocatalytic activity. Rhodamine B can be completely degraded within 6min and about 90% of Cr(VI) can be reduced after 25min under the irradiation of visible light (λ>400nm).