Interface engineering of p-p Z-scheme BiOBr/Bi12O17Br2 for sulfamethoxazole photocatalytic degradation

The Z-scheme heterojunction has received widespread attention due to it can effectively improve the photocatalytic activity of photocatalytic materials. In this paper, a p-p Z-scheme hererojunction composed of bismuth oxybromide and oxygen-rich bismuth oxybromide was synthesized via facile one-step solvothermal method. Based on the characterization results, we demonstrated that the BiOBr/Bi12O17Br2 Z-scheme heterojunction was synthesized by intimate interface contact between BiOBr and Bi12O17Br2 p-type semiconductors. This endowed the heterojunction composite with excellent photogenerated carrier transfer ability and photogenerated electronhole separation performance compared with pure BiOBr and Bi12O17Br2 materials, which were proven by photoelectrochemical measurement, photoluminescence spectra. The maximum photocurrent of BiOBr/Bi12O17Br2 (approximate to 0.32 mu A) is approximately 3 times that of the original BiOBr (approximate to 0.08 mu A ) when light is irradiated. In addition, the BiOBr/Bi12O17Br2 p-p Z-scheme composite photocatalyst had good photocatalytic activity for sulfamethoxazole, with .O2  free radicals as the main active species. It could photodegrade 99% sulfamethoxazole under light irradiation at 365 nm, and its degradation rate was approximately 13 times that of BiOBr and 1.5 times that of Bi12O17Br2 materials. Notably, BiOBr/Bi12O17Br2 exhibited an excellent performance after 4 consecutive runs. Besides, the possible degradation pathway of sulfamethoxazole was proposed. This work has reference significance for the construction of p-p Z-scheme heterojunctions and the treatment of environmental contaminants.

Automated summary

In this study, a Z-scheme heterojunction composed of bismuth oxybromide and oxygen-rich bismuth oxybromide was synthesized using a facile method, demonstrating enhanced photocatalytic activity for sulfamethoxazole degradation. The heterojunction exhibited superior photogenerated carrier transfer ability and significantly increased photocurrent under light irradiation compared to pure materials. This work provides valuable insights for the development of Z-scheme heterojunctions and environmental contaminant treatment.