Preparation of magnetically recoverable and Z-scheme BaFe12O19/AgBr composite for degradation of 2-Mercaptobenzothiazole and Methyl orange under visible light

Abstract

Here, a series of BaFe12O19/AgBr magnetic recyclable composites were designed for the removal of 2‑Mercaptobenzothiazole (MBT) and Methyl orange (MO) under visible light. The vibrating sample magnetometer test demonstrated that composites exhibit superior magnetic recyclability. Among all composites, 10% BaFe12O19/AgBr exhibited the highest reaction rate (0.1005 min−1) of MBT degradation, which was about 3.32 and 71.79 times higher than that of pure AgBr (0.0302 min−1) and BaFe12O19 (0.0014 min−1), respectively. Besides, the composites also exhibited obviously improved photocatalytic MO degradation properties. The excellent photocatalytic activity could be ascribed to the efficient separation of photo-induced charge carriers, which was certificated by cyclic voltammogram (CV), transient photocurrent tests, electrochemical impedance spectroscopy (EIS) and photoluminescence (PL) spectra. Capture experiments proved that O2−, h+ and OH are the main active species in the process of MBT degradation, which matches well with the results of electron spin resonance (ESR) measurements. Moreover, the test of Mott-Schottky plots verified the flat band potentials of catalysts. At last, a possible Z-scheme reaction mechanism for the photocatalytic system was proposed. This work will provide theoretical guidance for the construction of magnetically recyclable Z-type photocatalysts.