Preparation of nanofiber Co–BiVO4/Bi2O3 p-n heterojunction for high efficiency photocatalytic degradation of organic pollutants.

In recent years, water pollution caused by organic pollutants and antibiotic residues has become increasingly serious, posing a serious threat to human health and ecosystems. In this paper, Co–BiVO 4 /Bi 2 O 3 heterojunction was successfully prepared by electrospinning of Co3+ doped monoclinic BiVO 4 nanofibers and Bi 2 O 3. The photocatalytic degradation of chlortetracycline hydrochloride (CTC·HCl) and 2-mercaptobenzothiazole (MBT) in water was tested by simulating visible light conditions. The degradation efficiency of CTC·HCl by 3Co–BiVO 4 /Bi 2 O 3 -0.8 reached 90.5 % within 30 min, and the degradation rates were 3.93 and 7.06 times that of BiVO 4 and Bi 2 O 3 , respectively. At the same time, the degradation efficiency of MBT by 3Co–BiVO 4 /Bi 2 O 3 -0.8 reached 97.7 % within 40 min, and the degradation rates were 8.93 and 41.80 times that of BiVO 4 and Bi 2 O 3 , respectively. In addition, the photocatalytic performance of the catalyst and potassium persulfate (PS) co-system on pollutants was investigated. When 0.5 mM PS and a small amount of 3Co–BiVO 4 /Bi 2 O 3 -0.8 catalyst were added, the degradation efficiency of CTC·HCl and MBT could reach 87.6 % and 92.8 % in a short time. Furthermore, the work function and difference of the material were calculated by density functional theory (DFT), and the charge transfer mechanism of the p-n heterojunction was further determined. Finally, the intermediate products, degradation pathways and reaction mechanisms of MBT degradation were analyzed in detail by high performance liquid chromatography-mass spectrometry (HPLC-MS). Therefore, this study provides a potential effective way for the treatment of water pollution. [Display omitted] [ABSTRACT FROM AUTHOR]