Synthesis of stable and easily recycled ferric oxides assisted by Rhodamine B for efficient degradation of organic pollutants in heterogeneous photo-Fenton system

Ferric oxides with enhanced catalytic activity were successfully prepared via a facile hydrothermal process with the addition of Rhodamine B (RhB) followed by calcination. The catalytic performance of the catalyst was investigated by the degradation of RhB and 4-nitrophenol (4-NP) with the participation of H2O2 and visible light irradiation. The results demonstrate that the introduction of RhB into the hydrothermal process greatly enhanced the photo-Fenton catalytic performance of the catalysts for pollutants removal. Under the preferred conditions, the degradation rate of RhB (10 mg/L) and 4-NP (20 mg/L) by the Fe-RhB catalyst was over 99% and 80% within 40 min and 16 min, respectively. Furthermore, the Fe-RhB catalyst exhibited high catalytic activity for the degradation of RhB in a wide pH range from 2.9 to 10.7. More importantly, the catalyst was easily separated by external magnetic field to be reused and it still kept high activity and good stability after five cycles. Finally, the possible mechanism of the pollutants degradation was recommended. This research may provide new insight into the development of new heterogeneous photo-Fenton catalyst with high catalytic activity and easy-recovery. (C) 2018 Elsevier Ltd. All rights reserved.