Enhanced photocatalytic degradation of oxytetracycline by Z-scheme heterostructure ZIF-8/Bi4O5Br2 4 O 5 Br 2

Semiconductor photocatalysis technology has a wide range of application in the treatment of environmental pollution. In this study, the Z-scheme heterojunction photocatalyst ZIF-8/Bi4O5Br2 4 O 5 Br 2 was synthesized by hydro- thermal method. The morphology, structure, mechanism and photocatalytic performance of the materials were studied. Under simulated sunlight illumination for 60 minutes, the degradation efficiency of oxytetracycline (15 mg center dot L-1)- 1 ) reached 94.2 %. In light of density functional theory calculation and liquid chromatography-mass spectrometry, the attack sites and degradation pathways of OTC were determined. The consequence of free radical capture test and electron paramagnetic resonance detection showed that center dot O2-, 2- , center dot OH and h+ + were the primary active substances. Based on the analysis above, the charge transfer principle of Z-scheme heterojunction was further elucidation. It inhibited the recombination of photo carriers and improved the photocatalytic performance. This work provides a hopeful measure for photocatalytic degradation of OTC by Z-scheme heterojunction composite.