Heterogeneous Fenton degradation of ofloxacin catalyzed by magnetic nanostructured MnFeO with different morphologies.

Magnetic nanostructured MnFeO with different morphologies, synthesized via chemical co-precipitation and hydrothermal method, was assayed as heterogeneous Fenton catalysts. The as-prepared MnFeO catalysts were thoroughly characterized by various characterization methods, such as X-ray diffraction (XRD), N adsorption-desorption, transmission electron microscopy (TEM), magnetic hysteresis loops, temperature-programmed reduction (TPR), and X-ray photoelectron spectroscopy (XPS). The catalytic activity of MnFeO catalysts was evaluated in the heterogeneous Fenton degradation of ofloxacin (OFX). In our study, the morphology exhibited a critical impact on the catalytic activity of MnFeO. For example, MnFeO nanorods (MnFeO-NR) had a higher catalytic activity than MnFeO nanospheres (MnFeO-NS) and MnFeO nanocubes (MnFeO-NC) in OFX removal and HO decomposition. Notably, the catalytic activity was remarkably enhanced with increasing the relative amount of Mn and Fe species on the surface. Based on the results from quenching experiments and quantitative determination of •OH radicals, a possible catalytic mechanism of MnFeO was proposed. In addition, the stability and reusability of MnFeO-NR was ascertained, as the results suggested that MnFeO-NR was a stable and easily separated catalyst for heterogeneous Fenton process.