Green and efficient degradation of cefixime by 3D flower-like BiOBr: Performance and degradation pathway

Abstract

Surface property and microstructure significantly affect the photocatalytic activity of photocatalysts. In this work, a facile precipitation method with simply controlling the pH value was employed to prepare 3D flower-like BiOBr photocatalyst. The well-ordered nano lamellae of this 3D flower-like BiOBr can not only help facilitate the photogenerated charge carrier pairs transfer and separation, but also promote the sunlight absorption between the plenty of lamellae, consequently enhance the photocatalytic activity of the BiOBr photocatalyst. According to the photocatalytic experiments, the BiOBr-5 photocatalyst (5 represents the pH values) showed superior photocatalytic activity than other BiOBr-x samples, and the BiOBr-5 can degrade Rhodamine B (RhB) completely under 30 min visible light irradiation, while the degradation rate of cefixime (CEFs) was about 86.79% after 120 min visible light irradiation. Moreover, cefixime can be degraded to small molecule then continue to degrade CO2 and H2O to avoid the secondary pollution. Based on the suitable conduction band (CB, −0.49 eV) and valence band (VB, 2.41 eV) positions of BiOBr photocatalyst,·O2- and·OH can generate and participate in photocatalytic process to improve the degradation efficiency of organic pollutants. This work has provided an example for preparation of morphology-dependent photocatalyst to degrade organic pollutants.