Preparation and visible light catalytic degradation of magnetically recyclable ZnFe2O4/BiOBr flower-like microspheres

Abstract

The construction of a binary heterojunction is a crucial method for solving the low separation efficiency and photon utilization of BiOBr (BOB) photogeneration carriers. In this study, magnetic recyclable ZnFe2O4/BiOBr (ZFB) heterojunction microspheres containing oxygen vacancies were prepared using a two-step solvothermal method. The results of X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and Brunauer–Emmett–Teller analysis show that ZnFe2O4 (ZFO) induces the growth of a nanolayer structure on the surface of BOB, the diffraction peak intensity ratio of I(102)/I(110) increases, and the specific surface area increases significantly. The analysis of photoelectric characteristics indicates that compared with BOB, ZFB has a smaller bandgap, a larger visible response range, and a higher photogenerated carrier migration and separation efficiency. ZFB can significantly degrade the activated benzene ring in organic molecules, with the degradation efficiency of Rhodamine B (RhB), norfloxacin (NOR), and sulfadiazine (SDZ) reaching 99.04 %, 91.70 %, and 86.64 %, respectively. Under the magnetic recovery, the five-cycle degradation performance retention rate reaches more than 92 %. Holes and superoxide radicals are the main active substances of ZFB photocatalytic materials for degradation of micropollutants. This research provides an idea for the preparation of a green and efficient photocatalytic material with high recyclable efficiency, which can simultaneously degrade various micropollutants in organic wastewater.