FeVO4 as a highly active heterogeneous Fenton-like catalyst towards the degradation of Orange II

The iron vanadate, FeVO4, was prepared and characterized by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) surface area, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM). It was found that FeVO4 could effectively catalyze H2O2 to generate active hydroxyl radical OH, which was confirmed with electron spin resonance (ESR) spin-trapping technique. Therefore, it was employed as a heterogeneous Fenton-like catalyst in the present contribution, and its catalytic activity was mainly evaluated in terms of the degradation efficiency of Orange II. Compared with the conventional heterogeneous Fenton-like catalysts, α-Fe2O3, Fe3O4 and γ-FeOOH, FeVO4 possessed a much higher catalytic activity. The high catalytic activity possibly involved in a special two-way Fenton-like mechanism, that is, the activation of H2O2 by both Fe(III) and V(V) in FeVO4. Moreover, FeVO4 possessed a wide applicable pH range and its catalytic activity was slightly affected by the solution pH values in the range of 3–8.