Enhanced magnetic property and photocatalytic activity of UV-light responsive N-doped Fe2O3/FeVO4 heterojunction

Magnetic N-doped Fe2O3/FeVO4 heterostructure photocateysts with a rod-like structure had been successfully obtained by the hydrothermal method. The as-obtained products were characterized by XRD, SEM, TEM, XPS, DRS, PL and BET analysis. UV-light responsive photodegradation of Rhodamine B (RhB) was studied to evaluate the photocatalytic properties of the products. The results reveal that N-doped Fe2O3/FeVO4 heterojunctions with triclinic FeVO4 (P-1) and trigonal alpha-Fe2O3 (R-3c:H) exhibit the higher photocatalytic activity than that of the pure FeVO4. The N-doped Fe2O3/FeVO4 (R-N=0.75) heterojunction with the maximum content of alpha-Fe2O3 (30.46%) shows the best photocatalytic activity under UV-light irradiation, which can efficiently catalyze the degradation of RhB up to 90% at 180 min. The obtained data are used to analyze the enhanced photocatalytic mechanism. The doped N-3(-) ions provide an impurity level to capture the electrons produced from the valence band of FeVO4 and these electrons can subsequently be transferred to the surface adsorbed O-2 to produce O-2(-). Furthermore, the high Ms value (20.78 emu/g) of the N-doped Fe2O3/FeVO4 (R-N=0.75) heterojunction is strong enough to maintain their good performance of magnetic recovery after the photocatalytic reactions. (C) 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved.