Preparation and Properties of 3D Spherical Bi2S3/Bi2O2CO3 Photocatalytic Materials Self-Assembled by 2D Nanosheets

The micro-morphology of photocatalytic materials has a great influence on their photocatalytic performance. Quantum dots can provide the plasmon resonance effect and broaden the wavelength range of light absorption. In this study, a kind of 3D spherical flower-like structure was constructed by self-assembly of 2D nanosheets, the Bi₂S₃ particles with 5 ± 1 nm diameter were modified on the surfaces of Bi₂O₂CO₃ nanosheets to prepare the Bi₂S₃/Bi₂O₂CO₃ composite. The energy level difference (0.45 eV) between the conduction bands (CB) of Bi₂S₃ and Bi₂O₂CO₃ led to which the e⁻ was transferred to CB of Bi₂O₂CO₃. The energy level difference (0.83 eV) between the CB of Bi₂O₂CO₃ and the valence band (VB) of Bi₂S₃ was much smaller than the band gap (1.28 eV) of Bi₂S₃, and it led to which the electrons on the CB of Bi₂O₂CO₃ were recombined with the holes on the VB of Bi₂S₃. A kind of innovative type heterojunction was constructed between Bi₂S₃ and Bi₂O₂CO₃, which encouraged the photogenerated h⁺ and ·OH to be located on the VB of Bi₂O₂CO₃ with the strongest oxidation potential, the prepared material showed excellent performance for the photodegradation of RhB, and the active groups were also controlled in the photocatalysis process.