Visible-Light-Driven Photocatalytic Activity of Magnetic BiOBr/SrFe₁₂O₁₉ Nanosheets

• Main Authors: Taiping Xie, Jiao Hu, Jun Yang, Chenglun Liu, Longjun Xu, Jiankang Wang, Yuan Peng, Songli Liu, Xiuyu Yin, Yuanzhen Lu
• Format: Article
• Language: English
• Published: MDPI AG 2019-05-01
• Series: Nanomaterials
• Subjects: BiOBr/SrFe₁₂O₁₉; photocatalyst; Rhodamine B; photodegradation rate; magnetic photocatalyst
• Online Access: https://www.mdpi.com/2079-4991/9/5/735

Magnetic BiOBr/SrFe₁₂O₁₉ nanosheets were successfully synthesized using the hydrothermal method. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and UV-visible diffused reflectance spectra (UV-DRS), and the magnetic properties were tested using a vibration sample magnetometer (VSM). The as-produced composite with an irregular flaky-shaped aggregate possesses a good anti-demagnetization ability (Hc = 861.04 G) and a high photocatalytic efficiency. Under visible light (λ > 420 nm) and UV light-emitting diode (LED) irradiation, the photodegradation rates of Rhodamine B (RhB) using BiOBr/SrFe₁₂O₁₉ (5 wt %) (BOB/SFO-5) after 30 min of reaction were 97% and 98%, respectively, which were higher than that using BiOBr (87%). The degradation rate of RhB using the recovered BiOBr/5 wt % SrFe₁₂O₁₉ (marked as BOB/SFO-5) was still more than 85% in the fifth cycle, indicating the high stability of the composite catalyst. Meanwhile, after five cycles, the magnetic properties were still as stable as before. The radical-capture experiments proved that superoxide radicals and holes were main active species in the photocatalytic degradation of RhB.