A Stable Fe2O3/Expanded Perlite Composite Catalyst for Degradation of Rhodamine B in Heterogeneous Photo-Fenton System

A stable and efficient Fe2O3/expanded perlite (Fe2O3-Ep) composite catalyst was synthesized by a simple hydrothermal method for degradation of refractory contaminants in heterogeneous photo-Fenton system. X-ray diffraction and FT-IR analyses confirmed the presence of the Fe2O3 in the synthesized catalyst. The catalytic activity of the Fe2O3-Ep catalyst was evaluated by the degradation of rhodamine B (RhB, 5 mg/L) and metronidazole (MET, 5 mg/L) in the presence of H2O2 under visible light irradiation. The Fe2O3-Ep catalyst exhibited high efficiency for degradation of RhB at a wide pH range from 2 to 10 and showed excellent catalytic property for decomposition of MET as well. The degradation ratio of RhB was achieved 99%, and the removal ratio of COD was 62% within 90 min at the best experimental conditions (0.5 g/L of Fe2O3-Ep catalyst, 2 mL/L of H2O2). Furthermore, iron leaching of the Fe2O3-Ep catalyst during the catalytic degradation reaction was negligible and the catalyst still exhibited high catalytic activity and stability after five cycles. These results show that the catalyst can be used as a highly efficient heterogeneous photo-Fenton catalyst for the degradation of non-biodegradable refractory pollutants in water.